In engineering, a factor of safety (FoS) or safety factor (SF) expresses how much stronger a system is than it needs to be for an intended load. Safety factors are often calculated using detailed analysis because comprehensive testing is impractical on many projects, such as bridges and buildings, but the structure's ability to carry a load must be determined to a reasonable accuracy. Many systems are intentionally built much stronger than needed for normal usage to allow for emergency situations, unexpected loads, misuse, or degradation (reliability). Margin of safety is a related measure, expressed as a relative change.
A crane is a machine used to move materials both vertically and horizontally, utilizing a system of a boom, hoist, wire ropes or chains, and sheaves for lifting and relocating heavy objects within the swing of its boom. The device uses one or more simple machines, such as the lever and pulley, to create mechanical advantage to do its work. Cranes are commonly employed in transportation for the loading and unloading of freight, in construction for the movement of materials, and in manufacturing for the assembling of heavy equipment.
Limit State Design (LSD), also known as Load And Resistance Factor Design (LRFD), refers to a design method used in structural engineering. A limit state is a condition of a structure beyond which it no longer fulfills the relevant design criteria. The condition may refer to a degree of loading or other actions on the structure, while the criteria refer to structural integrity, fitness for use, durability or other design requirements. A structure designed by LSD is proportioned to sustain all actions likely to occur during its design life, and to remain fit for use, with an appropriate level of reliability for each limit state. Building codes based on LSD implicitly define the appropriate levels of reliability by their prescriptions.
A bolted joint is one of the most common elements in construction and machine design. It consists of a male threaded fastener that captures and joins other parts, secured with a matching female screw thread. There are two main types of bolted joint designs: tension joints and shear joints.
In quantum information theory, a quantum channel is a communication channel which can transmit quantum information, as well as classical information. An example of quantum information is the general dynamics of a qubit. An example of classical information is a text document transmitted over the Internet.
Coiflets are discrete wavelets designed by Ingrid Daubechies, at the request of Ronald Coifman, to have scaling functions with vanishing moments. The wavelet is near symmetric, their wavelet functions have vanishing moments and scaling functions , and has been used in many applications using Calderón–Zygmund operators.
Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum.
An I-beam is any of various structural members with an Ɪ- or H-shaped cross-section. Technical terms for similar items include H-beam, I-profile, universal column (UC), w-beam, universal beam (UB), rolled steel joist (RSJ), or double-T. I-beams are typically made of structural steel and serve a wide variety of construction uses.
Portal frame is a construction technique where vertical supports are connected to horizontal beams or trusses via fixed joints with designed-in moment-resisting capacity. The result is wide spans and open floors.
In geotechnical engineering, bearing capacity is the capacity of soil to support the loads applied to the ground. The bearing capacity of soil is the maximum average contact pressure between the foundation and the soil which should not produce shear failure in the soil. Ultimate bearing capacity is the theoretical maximum pressure which can be supported without failure; allowable bearing capacity is the ultimate bearing capacity divided by a factor of safety. Sometimes, on soft soil sites, large settlements may occur under loaded foundations without actual shear failure occurring; in such cases, the allowable bearing capacity is based on the maximum allowable settlement. The allowable bearing pressure is the maximum pressure that can be applied to the soil without causing failure. The ultimate bearing capacity, on the other hand, is the maximum pressure that can be applied to the soil before it fails.
Steel Design, or more specifically, Structural Steel Design, is an area of structural engineering used to design steel structures. These structures include schools, houses, bridges, commercial centers, tall buildings, warehouses, aircraft, ships and stadiums. The design and use of steel frames are commonly employed in the design of steel structures. More advanced structures include steel plates and shells.
Allowable Strength Design (ASD) is a term used by the American Institute of Steel Construction (AISC) in the 14th Edition of the Manual of Steel Construction.
In solid mechanics and structural engineering, section modulus is a geometric property of a given cross-section used in the design of beams or flexural members. Other geometric properties used in design include: area for tension and shear, radius of gyration for compression, and second moment of area and polar second moment of area for stiffness. Any relationship between these properties is highly dependent on the shape in question. There are two types of section modulus, elastic and plastic:
A tension member is a structural element designed to carry loads primarily through tensile forces, meaning it is subjected to stretching rather than compression or bending. These members are integral components in engineering and architectural structures, such as trusses, bridges, towers, and suspension systems, where they provide stability, distribute loads, and resist deformation. Typically made from high-strength materials like steel, wire ropes, or composites, tension members are valued for their efficiency in transferring forces along their length while maintaining lightweight and durable construction. Their design and performance are crucial in ensuring the safety and functionality of structures subjected to dynamic and static loads.
Structural engineering depends upon a detailed knowledge of loads, physics and materials to understand and predict how structures support and resist self-weight and imposed loads. To apply the knowledge successfully structural engineers will need a detailed knowledge of mathematics and of relevant empirical and theoretical design codes. They will also need to know about the corrosion resistance of the materials and structures, especially when those structures are exposed to the external environment.
Slope stability analysis is a static or dynamic, analytical or empirical method to evaluate the stability of slopes of soil- and rock-fill dams, embankments, excavated slopes, and natural slopes in soil and rock. It is performed to assess the safe design of a human-made or natural slopes and the equilibrium conditions. Slope stability is the resistance of inclined surface to failure by sliding or collapsing. The main objectives of slope stability analysis are finding endangered areas, investigation of potential failure mechanisms, determination of the slope sensitivity to different triggering mechanisms, designing of optimal slopes with regard to safety, reliability and economics, and designing possible remedial measures, e.g. barriers and stabilization.
Concrete has relatively high compressive strength, but significantly lower tensile strength. The compressive strength is typically controlled with the ratio of water to cement when forming the concrete, and tensile strength is increased by additives, typically steel, to create reinforced concrete. In other words we can say concrete is made up of sand, ballast, cement and water.
This information sets out some of the basic considerations taken into account by the lifting design engineer.
An offshore crane shock absorber is a gas spring with hydraulic damping used to reduce dynamic loads during offshore lifting. The lifting capacity of the offshore crane can be increased significantly during lifting in high sea states if a shock absorber is fitted.
In cryptography, FourQ is an elliptic curve developed by Microsoft Research. It is designed for key agreements schemes and digital signatures (Schnorr), and offers about 128 bits of security. It is equipped with a reference implementation made by the authors of the original paper. The open source implementation is called FourQlib and runs on Windows and Linux and is available for x86, x64, and ARM. It is licensed under the MIT License and the source code is available on GitHub.
