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Physics Of Failure
Physics of failure is a technique under the practice of reliability design that leverages the knowledge and understanding of the processes and mechanisms that induce failure to predict reliability and improve product performance. Other definitions of Physics of Failure include: * A science-based approach to reliability that uses modeling and simulation to design-in reliability. It helps to understand system performance and reduce decision risk during design and after the equipment is fielded. This approach models the root causes of failure such as fatigue, fracture, wear, and corrosion. * An approach to the design and development of reliable product to prevent failure, based on the knowledge of root cause failure mechanisms. The Physics of Failure (PoF) concept is based on the understanding of the relationships between requirements and the physical characteristics of the product and their variation in the manufacturing processes, and the reaction of product elements and materials ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability Engineering
Reliability engineering is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. Reliability describes the ability of a system or component to function under stated conditions for a specified period of time. Reliability is closely related to availability, which is typically described as the ability of a component or system to function at a specified moment or interval of time. The reliability function is theoretically defined as the probability of success at time t, which is denoted R(t). This probability is estimated from detailed (physics of failure) analysis, previous data sets or through reliability testing and reliability modelling. Availability, testability, maintainability and maintenance are often defined as a part of "reliability engineering" in reliability programs. Reliability often plays the key role in the cost-effectiveness of systems. Reliability engineering deals with the prediction, prevention and mana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Current Density
In electromagnetism, current density is the amount of charge per unit time that flows through a unit area of a chosen cross section. The current density vector is defined as a vector whose magnitude is the electric current per cross-sectional area at a given point in space, its direction being that of the motion of the positive charges at this point. In SI base units, the electric current density is measured in amperes per square metre. Definition Assume that ''A'' (SI unit: m2) is a small surface centred at a given point ''M'' and orthogonal to the motion of the charges at ''M''. If ''I'' (SI unit: A) is the electric current flowing through ''A'', then electric current density ''j'' at ''M'' is given by the limit: :j = \lim_ \frac = \left.\frac \_, with surface ''A'' remaining centered at ''M'' and orthogonal to the motion of the charges during the limit process. The current density vector j is the vector whose magnitude is the electric current density, and whose dir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Plane Analysis
Critical plane analysis refers to the analysis of stresses or strains as they are experienced by a particular plane in a material, as well as the identification of which plane is likely to experience the most extreme damage. Critical plane analysis is widely used in engineering to account for the effects of cyclic, multiaxial load histories on the fatigue life of materials and structures. When a structure is under cyclic multiaxial loading, it is necessary to use multiaxial fatigue criteria that account for the multiaxial loading. If the cyclic multiaxial loading is nonproportional it is mandatory to use a proper multiaxial fatigue criteria. The multiaxial criteria based on the Critical Plane Method are the most effective criteria. For the plane stress case, the orientation of the plane may be specified by an angle in the plane, and the stresses and strains acting on this plane may be computed via Mohr's circle. For the general 3D case, the orientation may be specified via a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Finite Element Software Packages
This is a list of notable software packages that implement the finite element method for solving partial differential equations In mathematics, a partial differential equation (PDE) is an equation which imposes relations between the various partial derivatives of a multivariable function. The function is often thought of as an "unknown" to be solved for, similarly to .... Feature comparison This table is contributed by a FEA-compare For ease of maintenance of this table, please, first consider to contribute changes directly to the project instead of editing the table below, however, direct wiki edits are also valid and will be backported project, which provides an alternative view of this table with the first row and Feature column being fixed for ease of table exploration. References {{DEFAULTSORT:List Of Finite Elem ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Cycling
Power cycling is the act of turning a piece of equipment, usually a computer, off and then on again. Reasons for power cycling include having an electronic device reinitialize its set of configuration parameters or recover from an unresponsive state of its mission critical functionality, such as in a crash or hang situation. Power cycling can also be used to reset network activity inside a modem. It can also be among the first steps for troubleshooting an issue. Overview Power cycling can be done manually, usually using a switch on the device to be cycled; automatically, through some type of device, system, or network management monitoring and control; or by remote control; through a communication channel. In the data center environment, remote control power cycling can usually be done through a power distribution unit, over TCP/IP. In the home environment, this can be done through home automation powerline communications or IP protocols. Most Internet Service Providers publish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sherlock Automated Design Analysis
''Sherlock Automated Design Analysis'' is a software tool developed by DfR Solutions for analyzing, grading, and certifying the expected reliability of products at the circuit card assembly level. Based on the science of Physics of Failure, Sherlock predicts failure mechanism-specific failure rates over time using a combination of finite element method and material properties to capture stress values and first order analytical equations to evaluate damage evolution. The software is designed for use by design and reliability engineers and managers in the electronics industry. DfR Solutions is based in Beltsville, Maryland, USA, and was acquired by ANSYS, Inc. in May 2019. Approach Users upload either a complete design package, like ODB++ or IPC-2581, or individual data packets, such as Gerber, Bill of Materials, and Pick and Place files. Sherlock incorporates stresses from a variety of environments into its physics-based prediction algorithms, including elevated temperature, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 28 g of water per cubic metre of air at , but only 8 g of water per cubic metre of air at . Three primary measurements of humidity are widely employed: absolute, relative, and specific. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelvin
The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907). The Kelvin scale is an absolute thermodynamic temperature scale, meaning it uses absolute zero as its null (zero) point. Historically, the Kelvin scale was developed by shifting the starting point of the much-older Celsius scale down from the melting point of water to absolute zero, and its increments still closely approximate the historic definition of a degree Celsius, but since 2019 the scale has been defined by fixing the Boltzmann constant to be exactly . Hence, one kelvin is equal to a change in the thermodynamic temperature that results in a change of thermal energy by . The temperature in degree Celsius is now defined as the temperature in kelvins minus 273.15, meaning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Bias Temperature Instability
Negative-bias temperature instability (NBTI) is a key reliability issue in MOSFETs, a type of transistor aging. NBTI manifests as an increase in the threshold voltage and consequent decrease in drain current and transconductance of a MOSFET. The degradation is often approximated by a power-law dependence on time. It is of immediate concern in p-channel MOS devices (pMOS), since they almost always operate with negative gate-to-source voltage; however, the very same mechanism also affects nMOS transistors when biased in the accumulation regime, i.e. with a negative bias applied to the gate. More specifically, over time positive charges become trapped at the oxide-semiconductor boundary underneath the gate of a MOSFET. These positive charges partially cancel the negative gate voltage ''without'' contributing to conduction through the channel as electron holes in the semiconductor are supposed to. When the gate voltage is removed, the trapped charges dissipate over a time scale of mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Carrier Injection
Hot carrier injection (HCI) is a phenomenon in solid-state electronic devices where an electron or a “ hole” gains sufficient kinetic energy to overcome a potential barrier necessary to break an interface state. The term "hot" refers to the effective temperature used to model carrier density, not to the overall temperature of the device. Since the charge carriers can become trapped in the gate dielectric of a MOS transistor, the switching characteristics of the transistor can be permanently changed. Hot-carrier injection is one of the mechanisms that adversely affects the reliability of semiconductors of solid-state devices. Physics The term “hot carrier injection” usually refers to the effect in MOSFETs, where a carrier is injected from the conducting channel in the silicon substrate to the gate dielectric, which usually is made of silicon dioxide (SiO2). To become “hot” and enter the conduction band of SiO2, an electron must gain a kinetic energy of ~3.2& ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Dependent Dielectric Breakdown
Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to compare the duration of events or the intervals between them, and to quantify rates of change of quantities in material reality or in the conscious experience. Time is often referred to as a fourth dimension, along with three spatial dimensions. Time has long been an important subject of study in religion, philosophy, and science, but defining it in a manner applicable to all fields without circularity has consistently eluded scholars. Nevertheless, diverse fields such as business, industry, sports, the sciences, and the performing arts all incorporate some notion of time into their respective measuring systems. 108 pages. Time in physics is operationally defined as "what a clock reads". The physical nature of time is address ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaling Factor
In affine geometry, uniform scaling (or isotropic scaling) is a linear transformation that enlarges (increases) or shrinks (diminishes) objects by a ''scale factor'' that is the same in all directions. The result of uniform scaling is similarity (geometry), similar (in the geometric sense) to the original. A scale factor of 1 is normally allowed, so that congruence (geometry), congruent shapes are also classed as similar. Uniform scaling happens, for example, when enlarging or reducing a photograph, or when creating a scale model of a building, car, airplane, etc. More general is scaling with a separate scale factor for each axis direction. Non-uniform scaling (anisotropic scaling) is obtained when at least one of the scaling factors is different from the others; a special case is directional scaling or stretching (in one direction). Non-uniform scaling changes the shape of the object; e.g. a square may change into a rectangle, or into a parallelogram if the sides of the squar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
