TheInfoList

Structural engineering is a sub-discipline of
civil engineering Civil engineering is a professional engineering Regulation and licensure in engineering is established by various jurisdictions of the world to encourage public welfare, safety, well-being and other interests of the general public and to define ...
in which
structural engineer Structural engineers analyze, design, plan, and research structural components and structural system The term structural system or structural frame in structural engineering refers to the load-resisting sub-system of a building or object. The ...
s are trained to design the 'bones and muscles' that create the form and shape of man-made structures.
Structural engineers Structural engineers analyze, design, plan, and research structural components and structural system The term structural system or structural frame in structural engineering refers to the load-resisting sub-system of a building or object. The s ...
also must understand and calculate the
stability Stability may refer to: Mathematics *Stability theory, the study of the stability of solutions to differential equations and dynamical systems **Asymptotic stability **Linear stability **Lyapunov stability **Orbital stability **Structural stability ...
, strength, rigidity and earthquake-susceptibility of built structures for
building A building, or edifice, is a structure with a roof and walls standing more or less permanently in one place, such as a house or factory. Buildings come in a variety of sizes, shapes, and functions, and have been adapted throughout history for a ...

s and
nonbuilding structure A nonbuilding structure, also referred to simply as a structure, refers to any body or system of connected parts used to support a load that was not designed for continuous human occupancy. The term is used by architects, structural engin ...
s. The structural designs are integrated with those of other designers such as
architects An architect is a person who plans, designs and oversees the construction of buildings. To practice architecture means to provide services in connection with the design of buildings and the space within the site surrounding the buildings that ha ...

and building services engineer and often supervise the construction of projects by
contractors A general contractor, main contractor or prime contractor is responsible for the day-to-day oversight of a construction site, management of vendors and trades, and the communication of information to all involved parties throughout the course of a ...
on site. They can also be involved in the design of machinery, medical equipment, and vehicles where structural integrity affects functioning and safety. See
glossary of structural engineering This glossary of structural engineering terms pertains specifically to structural engineering and its sub-disciplines. Please see glossary of engineering for a broad overview of the major concepts of engineering. ''Most of the terms listed in glos ...
. Structural engineering theory is based upon applied
physical laws Scientific laws or laws of science are statements, based on repeated experiment An experiment is a procedure carried out to support, refute, or validate a hypothesis. Experiments provide insight into Causality, cause-and-effect by demonstrat ...

and
empirical Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and ...
knowledge of the structural performance of different materials and geometries. Structural engineering design uses a number of relatively simple structural concepts to build complex
structural system The term structural system or structural frame in structural engineering refers to the load-resisting sub-system of a building or object. The structural system transfers loads through interconnected elements or members. Commonly used structures ...
s. Structural engineers are responsible for making creative and efficient use of funds, structural elements and materials to achieve these goals.

# History

Structural engineering dates back to 2700 B.C.E. when the step pyramid for Pharaoh
Djoser Djoser (also read as Djeser and Zoser) was an ian of the during the and the founder of this epoch. He is also known by his names Tosorthros (from ) and Sesorthos (from ). He was the son of king and queen , but whether he also was the direc ...

was built by
Imhotep , burial_place = Saqqara Saqqara ( ar, سقارة, ), also spelled Sakkara or Saccara in English , is a vast, ancient burial ground in Egypt Egypt ( ; ar, مِصر ), officially the Arab Republic of Egypt, is a transcontinental ...

, the first engineer in history known by name. Pyramids were the most common major structures built by ancient civilizations because the structural form of a pyramid is inherently stable and can be almost infinitely scaled (as opposed to most other structural forms, which cannot be linearly increased in size in proportion to increased loads). The structural stability of the pyramid, whilst primarily gained from its shape, relies also on the strength of the stone from which it is constructed, and its ability to support the weight of the stone above it.CV The limestone blocks were often taken from a quarry near the building site and have a compressive strength from 30 to 250 MPa (MPa = Pa × 106). Therefore, the structural strength of the pyramid stems from the material properties of the stones from which it was built rather than the pyramid's geometry. Throughout ancient and medieval history most architectural design and construction were carried out by artisans, such as stonemasons and carpenters, rising to the role of master builder. No theory of structures existed, and understanding of how structures stood up was extremely limited, and based almost entirely on empirical evidence of 'what had worked before' and
intuition Intuition is the ability to acquire without recourse to conscious ing. Different fields use the word "intuition" in very different ways, including but not limited to: direct access to unconscious knowledge; unconscious cognition; inner sensing; ...

. Knowledge was retained by guilds and seldom supplanted by advances. Structures were repetitive, and increases in scale were incremental. No record exists of the first calculations of the strength of structural members or the behavior of structural material, but the profession of a structural engineer only really took shape with the Industrial Revolution and the re-invention of concrete (see . The physical sciences underlying structural engineering began to be understood in the Renaissance and have since developed into computer-based applications pioneered in the 1970s.

## Timeline

* 1452–1519
Leonardo da Vinci Leonardo di ser Piero da Vinci (15 April 14522 May 1519) was an Italian of the who was active as a painter, , engineer, scientist, theorist, sculptor and architect. While his fame initially rested on his achievements as a painter, he als ...

Galileo Galilei Galileo di Vincenzo Bonaiuti de' Galilei (; 15 February 1564 – 8 January 1642) was an Italian astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the ...

published the book ''
Two New Sciences The ''Discourses and Mathematical Demonstrations Relating to Two New Sciences'' ( it, Discorsi e dimostrazioni matematiche intorno a due nuove scienze ) published in 1638 was Galileo Galilei Galileo di Vincenzo Bonaiuti de' Galilei (; ...
'' in which he examined the failure of simple structures. * 1660:
Hooke's law The balance wheel at the core of many mechanical clocks and watches depends on Hooke's law. Since the torque generated by the coiled spring is proportional to the angle turned by the wheel, its oscillations have a nearly constant period. Hooke ...
by
Robert Hooke Robert Hooke FRS FRS may also refer to: Government and politics * Facility Registry System, a centrally managed Environmental Protection Agency database that identifies places of environmental interest in the United States * Family Resources ...
. * 1687:
Isaac Newton Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician A mathematician is someone who uses an extensive knowledge of mathematics Mathematics (from Greek: ) includes the study of such topics a ...

published ''
Philosophiæ Naturalis Principia Mathematica (from Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman Republic, it bec ...
'', which contains his
laws of motionIn physics, a number of noted theories of the motion of objects have developed. Among the best known are: * Classical mechanics ** Newton's laws of motion ** Euler's laws of motion ** Cauchy momentum equation, Cauchy's equations of motion ** Kepler's ...
. * 1750: Euler–Bernoulli beam equation. * 1700–1782:
Daniel Bernoulli Daniel Bernoulli Fellows of the Royal Society, FRS (; – 27 March 1782) was a Swiss people, Swiss mathematician and physicist and was one of the many prominent mathematicians in the Bernoulli family from Basel. He is particularly remembered for ...
introduced the principle of
virtual work In mechanics Mechanics (Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approximate ...
. * 1707–1783:
Leonhard Euler Leonhard Euler ( ; ; 15 April 170718 September 1783) was a Swiss mathematician A mathematician is someone who uses an extensive knowledge of mathematics Mathematics (from Greek: ) includes the study of such topics as numbers ( and ) ...

developed the theory of
buckling In structural engineering Structural engineering is a sub-discipline of in which s are trained to design the 'bones and muscles' that create the form and shape of man-made structures. also must understand and calculate the , strength, and ...

of columns. * 1826:
Claude-Louis Navier Claude-Louis Navier (born Claude Louis Marie Henri Navier; ; 10 February 1785 – 21 August 1836), was a French mechanical engineer, affiliated with the French government, and a physicist whose work was specialized in continuum mechanics. The N ...

published a treatise on the elastic behaviors of structures. * 1873: Carlo Alberto Castigliano presented his dissertation "Intorno ai sistemi elastici", which contains his theorem for computing displacement as the partial derivative of the strain energy. This theorem includes the method of "least work" as a special case. * 1874: Otto Mohr formalized the idea of a statically indeterminate structure. * 1922: corrects the Euler–Bernoulli beam equation. * 1936:
Hardy Cross Hardy Cross (1885–1959) was an United States, American structural engineer and the developer of the moment distribution method for structural analysis of statically indeterminate structures. The method was in general use from c. 1935 until c. 1960 ...
' publication of the moment distribution method, an important innovation in the design of continuous frames. * 1941:
Alexander Hrennikoff Alexander Pavlovich Hrennikoff (russian: Александр Павлович Хренников; 11 November 1896 — 31 December 1984) was a Russia Russia (russian: link=no, Россия, , ), or the Russian Federation, is a country spannin ...
solved the discretization of plane elasticity problems using a lattice framework. * 1942:
Richard Courant Richard Courant (January 8, 1888 – January 27, 1972) was a German American German Americans (german: Deutschamerikaner, ) are Americans Americans are the Citizenship of the United States, citizens and United States nationality law, nation ...

divided a domain into finite subregions. * 1956: J. Turner, R. W. Clough, H. C. Martin, and L. J. Topp's paper on the "Stiffness and Deflection of Complex Structures" introduces the name "finite-element method" and is widely recognized as the first comprehensive treatment of the method as it is known today.

## Structural failure

The history of structural engineering contains many collapses and failures. Sometimes this is due to obvious negligence, as in the case of the Pétion-Ville school collapse, in which Rev. Fortin Augustin ''" constructed the building all by himself, saying he didn't need an engineer as he had good knowledge of construction"'' following a partial collapse of the three-story schoolhouse that sent neighbors fleeing. The final collapse killed 94 people, mostly children. In other cases structural failures require careful study, and the results of these inquiries have resulted in improved practices and a greater understanding of the science of structural engineering. Some such studies are the result of
forensic engineering Forensic engineering has been defined as ''"the investigation of failures - ranging from serviceability to catastrophic - which may lead to legal activity, including both civil and criminal".'' It includes the investigation of materials Mate ...
investigations where the original engineer seems to have done everything in accordance with the state of the profession and acceptable practice yet a failure still eventuated. A famous case of structural knowledge and practice being advanced in this manner can be found in a series of failures involving box girders which collapsed in Australia during the 1970s.

# Theory

Structural engineering depends upon a detailed knowledge of
applied mechanics Applied mechanics is a branch of the physical science Physical science is a branch of natural science that studies abiotic component, non-living systems, in contrast to life science. It in turn has many branches, each referred to as a "physical ...
,
materials science The interdisciplinary Interdisciplinarity or interdisciplinary studies involves the combination of two or more academic disciplines into one activity (e.g., a research project). It draws knowledge from several other fields like sociology, a ...
, and
applied mathematics Applied mathematics is the application of mathematical methods by different fields such as physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and be ...
to understand and predict how structures support and resist self-weight and imposed loads. To apply the knowledge successfully a structural engineer generally requires detailed knowledge of relevant empirical and theoretical design codes, the techniques of
structural analysis Structural analysis is the determination of the effects of load Load or LOAD may refer to: Aeronautics and transportation *Load factor (aeronautics), the ratio of the lift of an aircraft to its weight *Passenger load factor, the ratio of rev ...
, as well as some knowledge of the
corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable form such as oxide An oxide () is a chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecu ...

resistance of the materials and structures, especially when those structures are exposed to the external environment. Since the 1990s, specialist software has become available to aid in the design of structures, with the functionality to assist in the drawing, analyzing and designing of structures with maximum precision; examples include
AutoCAD AutoCAD is a commercial software, commercial computer-aided design (CAD) and technical drawing, drafting software application. Developed and marketed by Autodesk, AutoCAD was first released in December 1982 as a desktop app running on microcomputer ...
, StaadPro, ETABS, Prokon, Revit Structure, Inducta RCB, etc. Such software may also take into consideration environmental loads, such as earthquakes and winds.

# Profession

Structural engineers are responsible for engineering design and structural analysis. Entry-level structural engineers may design the individual structural elements of a structure, such as the beams and columns of a building. More experienced engineers may be responsible for the structural design and integrity of an entire system, such as a building. Structural engineers often specialize in particular types of structures, such as buildings, bridges, pipelines, industrial, tunnels, vehicles, ships, aircraft, and spacecraft. Structural engineers who specialize in buildings often specialize in particular construction materials such as concrete, steel, wood, masonry, alloys, and composites, and may focus on particular types of buildings such as offices, schools, hospitals, residential, and so forth. Structural engineering has existed since humans first started to construct their structures. It became a more defined and formalized profession with the emergence of architecture as a distinct profession from engineering during the industrial revolution in the late 19th century. Until then, the architect and the structural engineer were usually one and the same thing – the master builder. Only with the development of specialized knowledge of structural theories that emerged during the 19th and early 20th centuries, did the professional structural engineers come into existence. The role of a structural engineer today involves a significant understanding of both static and dynamic loading and the structures that are available to resist them. The complexity of modern structures often requires a great deal of creativity from the engineer in order to ensure the structures support and resist the loads they are subjected to. A structural engineer will typically have a four or five-year undergraduate degree, followed by a minimum of three years of professional practice before being considered fully qualified. Structural engineers are licensed or accredited by different learned societies and regulatory bodies around the world (for example, the Institution of Structural Engineers in the UK). Depending on the degree course they have studied and/or the jurisdiction they are seeking licensure in, they may be accredited (or licensed) as just structural engineers, or as civil engineers, or as both civil and structural engineers. Another international organisation is IABSE(International Association for Bridge and Structural Engineering). The aim of that association is to exchange knowledge and to advance the practice of structural engineering worldwide in the service of the profession and society.

# Specializations

## Building structures

Structural building engineering includes all structural engineering related to the design of buildings. It is a branch of structural engineering closely affiliated with
architecture upright=1.45, alt=Plan d'exécution du second étage de l'hôtel de Brionne (dessin) De Cotte 2503c – Gallica 2011 (adjusted), Plan of the second floor (attic storey) of the Hôtel de Brionne in Paris – 1734. Architecture (Latin ''archi ...

. Structural building engineering is primarily driven by the creative manipulation of materials and forms and the underlying mathematical and scientific ideas to achieve an end that fulfills its functional requirements and is structurally safe when subjected to all the loads it could reasonably be expected to experience. This is subtly different from architectural design, which is driven by the creative manipulation of materials and forms, mass, space, volume, texture, and light to achieve an end which is aesthetic, functional, and often artistic. The architect is usually the lead designer on buildings, with a structural engineer employed as a sub-consultant. The degree to which each discipline leads the design depends heavily on the type of structure. Many structures are structurally simple and led by architecture, such as multi-story office buildings and housing, while other structures, such as
tensile structure A tensile structure is a construction Construction is a general term meaning the and to form , , or ,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and ...
s,
shells Shell may refer to: Architecture and design * Shell (structure), a thin structure **Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses **Thin-shell structure, **Oil company Science Biology * Seashell ...
and
gridshell (during construction), Vyksa near Nizhny Novgorod, 1897 , a wooden gridshell structure designed by Frei Otto Image:Saville Building roof interior gridshell.jpg, Interior of the gridshell Savill Building A gridshell is a structure which derives i ...

s are heavily dependent on their form for their strength, and the engineer may have a more significant influence on the form, and hence much of the aesthetic, than the architect. The structural design for a building must ensure that the building can stand up safely, able to function without excessive deflections or movements which may cause fatigue of structural elements, cracking or failure of fixtures, fittings or partitions, or discomfort for occupants. It must account for movements and forces due to temperature, creep, cracking, and imposed loads. It must also ensure that the design is practically buildable within acceptable manufacturing tolerances of the materials. It must allow the architecture to work, and the building services to fit within the building and function (air conditioning, ventilation, smoke extract, electrics, lighting, etc.). The structural design of a modern building can be extremely complex and often requires a large team to complete. Structural engineering specialties for buildings include: *
Earthquake engineering Earthquake engineering is an interdisciplinary Interdisciplinarity or interdisciplinary studies involves the combination of two or more academic disciplines into one activity (e.g., a research project). It draws knowledge from several other ...
Fire engineering Fire protection engineering is the application of science and engineering principles to protect people, property, and their environments from the harmful and destructive effects of fire and smoke. It encompasses engineering which focuses on fire d ...
* * *
Wind engineering Wind engineering is a subset of mechanical engineering Mechanical engineering is an engineering Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, road ...

## Earthquake engineering structures

Earthquake engineering structures are those engineered to withstand
earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth Earth is the third planet from the Sun and the only astronomical object known ...

s. The main objectives of earthquake engineering are to understand the interaction of
structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. ...

s with the shaking ground, foresee the consequences of possible earthquakes, and design and construct the structures to
perform PerForm and PerForm PRO were electronic form programs, initially designed to work under Graphics Environment Manager, GEM in DOS. Later versions were designed to work in Windows 3.1, at which point it was succeeded by FormFlow. The initial version ...
during an earthquake. Earthquake-proof structures are not necessarily extremely strong like the El Castillo pyramid at Chichen Itza shown above. One important tool of
earthquake engineering Earthquake engineering is an interdisciplinary Interdisciplinarity or interdisciplinary studies involves the combination of two or more academic disciplines into one activity (e.g., a research project). It draws knowledge from several other ...
is
base isolation Seismic base isolation, also known as base isolation, or base isolation system, is one of the most popular means of protecting a structure against earthquake forces. It is a collection of structural elements which should substantially decoupl ...
, which allows the base of a structure to move freely with the ground.

## Civil engineering structures

Civil structural engineering includes all structural engineering related to the built environment. It includes: The structural engineer is the lead designer on these structures, and often the sole designer. In the design of structures such as these, structural safety is of paramount importance (in the UK, designs for dams, nuclear power stations and bridges must be signed off by a
chartered engineer Regulation and licensure in engineering is established by various jurisdictions of the world to encourage public welfare, safety, well-being and other interests of the general public and to define the licensure Licensure means a restricted pract ...
). Civil engineering structures are often subjected to very extreme forces, such as large variations in temperature, dynamic loads such as waves or traffic, or high pressures from water or compressed gases. They are also often constructed in corrosive environments, such as at sea, in industrial facilities, or below ground.

## Mechanical structures

The principles of structural engineering apply to a variety of mechanical (moveable) structures. The design of static structures assumes they always have the same geometry (in fact, so-called static structures can move significantly, and structural engineering design must take this into account where necessary), but the design of moveable or moving structures must account for
fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
, variation in the method in which load is resisted and significant deflections of structures. The forces which parts of a machine are subjected to can vary significantly and can do so at a great rate. The forces which a boat or aircraft are subjected to vary enormously and will do so thousands of times over the structure's lifetime. The structural design must ensure that such structures can endure such loading for their entire design life without failing. These works can require mechanical structural engineering: * Boilers and pressure vessels * Coachworks and carriages * Cranes *
Elevator An elevator (North American English North American English (NAmE, NAE) is the most generalized variety (linguistics), variety of the English language as spoken in the United States and Canada. Because of their related histories and ...

s *
Escalator An escalator is a moving staircase which carries people between floors of a building or structure. It consists of a motor An engine or motor is a machine A machine is a man-made device that uses power to apply forces and control ...

s * Marine vessels and hulls

## Aerospace structures

Aerospace structure types include launch vehicles, (
Atlas Blaeu's world map, originally prepared by Joan Blaeu for his ''Atlas Maior">Joan_Blaeu.html" ;"title="world map, originally prepared by Joan Blaeu">world map, originally prepared by Joan Blaeu for his ''Atlas Maior'', published in the first b ...
,
Delta Delta commonly refers to: * Delta (letter) (Δ or δ), a letter of the Greek alphabet * River delta, a landform at the mouth of a river * D (NATO phonetic alphabet: "Delta"), the fourth letter of the modern English alphabet * Delta Air Lines, an Ame ...
, Titan),
missiles In military terminology, a missile is a missile guidance, guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when in rocket f ...
(ALCM, Harpoon),
Hypersonic In aerodynamics, a hypersonic speed is one that greatly exceeds the speed of sound, often stated as starting at speeds of speed of sound, Mach 5 and above. The precise Mach number at which a craft can be said to be flying at hypersonic speed v ...
vehicles (Space Shuttle),
military aircraft A military aircraft is any fixed-wing A fixed-wing aircraft is a heavier-than-air flying machine, such as an airplane An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a j ...
(F-16, F-18) and commercial aircraft (
Boeing The Boeing Company () is an American multinational corporation A multinational company (MNC) is a corporate A corporation is an organization—usually a group of people or a company A company, abbreviated as co., is a Legal personal ...

777, MD-11). Aerospace structures typically consist of thin plates with stiffeners for the external surfaces, bulkheads, and frames to support the shape and fasteners such as welds, rivets, screws, and bolts to hold the components together.

## Nanoscale structures

A
nanostructure 250px, The DNA structure at left (schematic shown) will self-assemble into the structure visualized by atomic force microscopy at right. Image from Strong. A nanostructure is a structure A structure is an arrangement and organization of interre ...

is an object of intermediate size between molecular and microscopic (micrometer-sized) structures. In describing nanostructures it is necessary to differentiate between the number of dimensions on the nanoscale. Nanotextured surfaces have one dimension on the nanoscale, i.e., only the thickness of the surface of an object is between 0.1 and 100 nm.
Nanotube A nanotube is a nanometer The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re, -er, American spelling) is a units of ...
s have two dimensions on the nanoscale, i.e., the diameter of the tube is between 0.1 and 100 nm; its length could be much greater. Finally, spherical
nanoparticles A nanoparticle or ultrafine particle is usually defined as a particle of matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched ...

have three dimensions on the nanoscale, i.e., the particle is between 0.1 and 100 nm in each spatial dimension. The terms nanoparticles and ultrafine particles (UFP) often are used synonymously although UFP can reach into the micrometer range. The term 'nanostructure' is often used when referring to magnetic technology.

## Structural engineering for medical science

Medical equipment (also known as armamentarium) is designed to aid in the diagnosis, monitoring or treatment of medical conditions. There are several basic types:
diagnostic Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic Logic is an interdisciplinary field which studies truth and reasoning. Inf ...
equipment includes medical imaging machines, used to aid in diagnosis; equipment includes infusion pumps, medical lasers, and LASIK surgical machines; medical monitors allow medical staff to measure a patient's medical state. Monitors may measure patient vital signs and other parameters including
ECG Electrocardiography is the process of producing an electrocardiogram (ECG or EKG). It is an electrogram of the heart The heart is a cardiac muscle, muscular Organ (biology), organ in most animals, which pumps blood through the blood ...

,
EEG Electroencephalography (EEG) is a method to record an electrogram of the electrical activity on the scalp The scalp is the anatomical area bordered by the human at the front, and by the at the sides and back. Structure The scalp is us ...

, blood pressure, and dissolved gases in the blood; diagnostic medical equipment may also be used in the home for certain purposes, e.g. for the control of diabetes mellitus. A
biomedical equipment technicianA biomedical engineering/equipment technician/technologist (BMET) or biomedical engineering/equipment specialist (BES or BMES) is typically an electro-mechanical technician A technician is a worker in a field of technology who is proficient in the r ...
(BMET) is a vital component of the healthcare delivery system. Employed primarily by hospitals, BMETs are the people responsible for maintaining a facility's medical equipment.

# Structural elements

Any structure is essentially made up of only a small number of different types of elements: *
Columns A column or pillar in architecture upright=1.45, alt=Plan d'exécution du second étage de l'hôtel de Brionne (dessin) De Cotte 2503c – Gallica 2011 (adjusted), Plan of the second floor (attic storey) of the Hôtel de Brionne in Par ...

* Beams * Plates *
Arch An arch is a vertical curved structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or interrelated elements that act according to ...

es *
Shells Shell may refer to: Architecture and design * Shell (structure), a thin structure **Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses **Thin-shell structure, **Oil company Science Biology * Seashell ...
* Catenaries Many of these elements can be classified according to form (straight, plane / curve) and dimensionality (one-dimensional / two-dimensional):

## Columns

Columns are elements that carry only axial force (compression) or both axial force and bending (which is technically called a beam-column but practically, just a column). The design of a column must check the axial capacity of the element and the buckling capacity. The buckling capacity is the capacity of the element to withstand the propensity to buckle. Its capacity depends upon its geometry, material, and the effective length of the column, which depends upon the restraint conditions at the top and bottom of the column. The effective length is $K*l$ where $l$ is the real length of the column and K is the factor dependent on the restraint conditions. The capacity of a column to carry axial load depends on the degree of bending it is subjected to, and vice versa. This is represented on an interaction chart and is a complex non-linear relationship.

## Beams

A beam may be defined as an element in which one dimension is much greater than the other two and the applied loads are usually normal to the main axis of the element. Beams and columns are called line elements and are often represented by simple lines in structural modeling. *
cantilever A cantilever is a rigid structural elementStructural elements are used in structural analysis Structural analysis is the determination of the effects of load Load or LOAD may refer to: Aeronautics and transportation *Load factor (aeronaut ...

ed (supported at one end only with a fixed connection) * simply supported (fixed against vertical translation at each end and horizontal translation at one end only, and able to rotate at the supports) * fixed (supported in all directions for translation and rotation at each end) * continuous (supported by three or more supports) * a combination of the above (ex. supported at one end and in the middle) Beams are elements that carry pure bending only. Bending causes one part of the section of a beam (divided along its length) to go into compression and the other part into tension. The compression part must be designed to resist buckling and crushing, while the tension part must be able to adequately resist the tension.

## Trusses

A
truss A truss is an assembly of ''members'' such as beams, connected by ''nodes'', that creates a rigid structure. In engineering, a truss is a structure A structure is an arrangement and organization of interrelated elements in a material object ...

is a structure comprising members and connection points or nodes. When members are connected at nodes and forces are applied at nodes members can act in tension or compression. Members acting in compression are referred to as compression members or
strut A strut is a structural component commonly found in engineering Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The d ...

s while members acting in tension are referred to as tension members or
ties TIES may refer to: * TIES, Teacher Institute for Evolutionary Science * TIES, The Interactive Encyclopedia System * TIES, Time Independent Escape SequenceThe Time Independent Escape Sequence, or TIES, is a modem protocol standard invented to avo ...
. Most trusses use gusset plates to connect intersecting elements. Gusset plates are relatively flexible and unable to transfer bending moments. The connection is usually arranged so that the lines of force in the members are coincident at the joint thus allowing the truss members to act in pure tension or compression. Trusses are usually used in large-span structures, where it would be uneconomical to use solid beams.

## Plates

Plates carry bending in two directions. A concrete flat slab is an example of a plate. Plates are understood by using continuum mechanics, but due to the complexity involved they are most often designed using a codified empirical approach, or computer analysis. They can also be designed with yield line theory, where an assumed collapse mechanism is analyzed to give an upper bound on the collapse load. This technique is used in practice but because the method provides an upper-bound, i.e. an unsafe prediction of the collapse load, for poorly conceived collapse mechanisms great care is needed to ensure that the assumed collapse mechanism is realistic.

## Shells

Shells derive their strength from their form and carry forces in compression in two directions. A dome is an example of a shell. They can be designed by making a hanging-chain model, which will act as a catenary in pure tension and inverting the form to achieve pure compression.

## Arches

Arches carry forces in compression in one direction only, which is why it is appropriate to build arches out of masonry. They are designed by ensuring that the line of thrust of the force remains within the depth of the arch. It is mainly used to increase the bountifulness of any structure.

## Catenaries

Catenaries derive their strength from their form and carry transverse forces in pure tension by deflecting (just as a tightrope will sag when someone walks on it). They are almost always cable or fabric structures. A fabric structure acts as a catenary in two directions.

# Materials

Structural engineering depends on the knowledge of materials and their properties, in order to understand how different materials support and resist loads. It also involves a knowledge of Corrosion engineering to avoid for example galvanic coupling of dissimilar materials. Common structural materials are: * Iron: wrought iron, cast iron * Concrete: reinforced concrete, prestressed concrete * Alloy: steel, stainless steel * Masonry * Timber: hardwood, softwood * Aluminium * Composite materials: plywood * Other structural materials: adobe, bamboo, carbon fibre, fiber reinforced plastic, mudbrick, roofing materials

* Glossary of structural engineering * Aircraft structures * Architects * Architectural engineering * Building officials * Building services engineering * Civil engineering * Construction engineering * Corrosion engineering *
Earthquake engineering Earthquake engineering is an interdisciplinary Interdisciplinarity or interdisciplinary studies involves the combination of two or more academic disciplines into one activity (e.g., a research project). It draws knowledge from several other ...
* Forensic engineering * Index of structural engineering articles * List of bridge disasters * List of structural engineers * Mechanical engineering * Nanostructure * Prestressed structure * Structurae * Structural engineer * Structural engineering software * Structural fracture mechanics * Structural failure * Structural robustness * Structural steel * Structural testing

# References

* Hibbeler, R. C. (2010). ''Structural Analysis''. Prentice-Hall. * Blank, Alan; McEvoy, Michael; Plank, Roger (1993). ''Architecture and Construction in Steel''. Taylor & Francis. . * Hewson, Nigel R. (2003). ''Prestressed Concrete Bridges: Design and Construction''. Thomas Telford. . * Heyman, Jacques (1999). ''The Science of Structural Engineering''. Imperial College Press. . * Hosford, William F. (2005). ''Mechanical Behavior of Materials''. Cambridge University Press. .

* Blockley, David (2014). ''A Very Short Introduction to Structural Engineering''. Oxford University Press . * Bradley, Robert E.; Sandifer, Charles Edward (2007). ''Leonhard Euler: Life, Work, and Legacy''. Elsevier. . * Chapman, Allan. (2005). ''England's Leornardo: Robert Hooke and the Seventeenth Century's Scientific Revolution.'' CRC Press. . * Dugas, René (1988). ''A History of Mechanics''. Courier Dover Publications. . * Feld, Jacob; Carper, Kenneth L. (1997). ''Construction Failure''. John Wiley & Sons. . * Galilei, Galileo. (translators: Crew, Henry; de Salvio, Alfonso) (1954). ''Dialogues Concerning Two New Sciences''. Courier Dover Publications. * Kirby, Richard Shelton (1990). ''Engineering in History''. Courier Dover Publications. . * Heyman, Jacques (1998). ''Structural Analysis: A Historical Approach''. Cambridge University Press. . * Labrum, E.A. (1994). ''Civil Engineering Heritage''. Thomas Telford. . * Lewis, Peter R. (2004). ''Beautiful Bridge of the Silvery Tay''. Tempus. * Mir, Ali (2001). ''Art of the Skyscraper: the Genius of Fazlur Khan''. Rizzoli International Publications. . * Rozhanskaya, Mariam; Levinova, I. S. (1996). "Statics" in Morelon, Régis & Rashed, Roshdi (1996). ''Encyclopedia of the History of Arabic Science'', vol. 2–3, Routledge. * Whitbeck, Caroline (1998). ''Ethics in Engineering Practice and Research''. Cambridge University Press. . * Hoogenboom P.C.J. (1998). "Discrete Elements and Nonlinearity in Design of Structural Concrete Walls", Section 1.3 Historical Overview of Structural Concrete Modelling, . * Nedwell, P.J.; Swamy, R.N.(ed) (1994). ''Ferrocement:Proceedings of the Fifth International Symposium''. Taylor & Francis. .

Structural Engineering Association – International

National Council of Structural Engineers Associations

Structural Engineering Institute
an institute of the American Society of Civil Engineers
Structurae database of structures

Structural Engineering Consultants

Structural Engineering Association – International

The EN Eurocodes are a series of 10 European Standards, EN 1990 – EN 1999, providing a common approach for the design of buildings and other civil engineering works and construction products
{{DEFAULTSORT:Structural Engineering Structural engineering, Civil engineering Engineering disciplines