Structural element in the context of Shell (structure)

Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage systems, pipelines, structural components of buildings, and railways.

Civil engineering is traditionally broken into a number of sub-disciplines. It is considered the second-oldest engineering discipline after military engineering, and it is defined to distinguish non-military engineering from military engineering. Civil engineering can take place in the public sector from municipal public works departments through to federal government agencies, and in the private sector from locally based firms to Fortune Global 500 companies.

A beam is a structural element that primarily resists loads applied laterally across its axis (an element designed to carry a load pushing parallel to its axis would be a strut or column). A beam's mode of deflection is primarily by bending, as loads produce reaction forces at the beam's support points and internal bending moments, shear, stresses, strains, and deflections. Beams are characterized by their manner of support, profile (shape of cross-section), equilibrium conditions, length, and material.

Beams are traditionally descriptions of building or civil engineering structural elements, where the beams are horizontal and carry vertical loads. However, any structure may contain beams, such as automobile frames, aircraft components, machine frames, and other mechanical or structural systems. Any structural element, in any orientation, that primarily resists loads applied laterally across the element's axis is a beam.

Soft-bodied organisms are organisms that lack rigid physical skeletons or frame, roughly corresponds to the group Vermes as proposed by Carl von Linné. The term typically refers to non-panarthropod invertebrates from the kingdom Animalia, although many non-vascular plants (mosses and algae), fungi (such as jelly fungus), lichens and slime molds can also be seen as soft-bodied organisms by definition.

All animals have a muscular system of some sort but, since myocytes are tensile actuator units that can only contract and pull but never push, some animals evolved rigid body parts upon which the muscles can attach and act as levers/cantilevers to redirect force and produce locomotive propulsion. These rigid parts also serve as structural elements to resist gravity and ambient pressure, as well as sometimes provide protective surfaces shielding internal structures from trauma and exposure to external thermal, chemical and pathogenic insults. Such physical structures are the commonly referred "skeletons", which may be internal (as in vertebrates, echinoderms and sponges) or external (as in arthropods and non-coleoid molluscs). However, many soft-bodied animals do still have a functional skeleton maintained by body fluid hydrostatics known as a hydroskeleton, such as that of earthworms, jellyfish, tapeworms, squids and an enormous variety of invertebrates from almost every phyla of the animal kingdom; and many have hardened teeth that allow them to chew, bite and burrow despite the rest of body being soft.

An endoskeleton (from Ancient Greek ἔνδον (éndon), meaning "inside", and σκελετός (skeletós), meaning "skeleton") is a structural frame (skeleton) — usually composed of mineralized tissue — on the inside of an animal, overlaid by soft tissues. Endoskeletons serve as structural support against gravity and mechanical loads, and provide anchoring attachment sites for skeletal muscles to transmit force and allow movements and locomotion.

Vertebrates and the closely related cephalochordates are the predominant animal clade with endoskeletons (made of mostly bone and sometimes cartilage, as well as notochordal glycoprotein and collagen fibers), although invertebrates such as sponges also have evolved a form of "rebar" endoskeletons made of diffuse meshworks of calcite/silica structural elements called spicules, and echinoderms have a dermal calcite endoskeleton known as ossicles. Some coleoid cephalopods (squids and cuttlefish) have an internalized vestigial aragonite/calcite-chitin shell known as gladius or cuttlebone, which can serve as muscle attachments but the main function is often to maintain buoyancy rather than to give structural support, and their body shape is largely maintained by hydroskeleton.

High-tech architecture, also known as structural expressionism, is a type of late modernist architecture that emerged in the 1970s, incorporating elements of high tech industry and technology into building design. High-tech architecture grew from the modernist style, utilizing new advances in technology and building materials. It emphasizes transparency in design and construction, seeking to communicate the underlying structure and function of a building throughout its interior and exterior. High-tech architecture makes extensive use of aluminium, steel, glass, and to a lesser extent concrete (the technology for which had developed earlier), as these materials were becoming more advanced and available in a wider variety of forms at the time the style was developing – generally, advancements in a trend towards lightness of weight.

High-tech architecture focuses on creating adaptable buildings through choice of materials, internal structural elements, and programmatic design. It seeks to avoid links to the past, and as such eschews building materials commonly used in older styles of architecture. Common elements include hanging or overhanging floors, a lack of internal load-bearing walls, and reconfigurable spaces. Some buildings incorporate prominent, bright colors in an attempt to evoke the sense of a drawing or diagram. High-tech utilizes a focus on factory aesthetics and a large central space serviced by many smaller maintenance areas to evoke a feeling of openness, honesty, and transparency.

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 can be classified into five major categories, depending on the type of primary stress that may arise in the members of the structures under major design loads. However any two or more of the basic structural types described in the following may be combined in a single structure, such as a building or a bridge in order to meet the structure's functional requirements.

A load-bearing wall or bearing wall is a wall that is an active structural element of a building, which holds the weight of the elements above it, by conducting its weight to a foundation structure below it.

Load-bearing walls are one of the earliest forms of construction. The development of the flying buttress in Gothic architecture allowed structures to maintain an open interior space, transferring more weight to the buttresses instead of to central bearing walls. In housing, load-bearing walls are most common in the light construction method known as "platform framing". In the birth of the skyscraper era, the concurrent rise of steel as a more suitable framing system first designed by William Le Baron Jenney, and the limitations of load-bearing construction in large buildings, led to a decline in the use of load-bearing walls in large-scale commercial structures.

In engineering, a housing or enclosure is a container, a protective exterior (e.g. shell) or an enclosing structural element (e.g. chassis or exoskeleton) designed to enable easier handling, provide attachment points for internal mechanisms (e.g. mounting brackets for electrical components, cables and pipings), maintain cleanliness of the contents by shielding dirt/dust, fouling and other contaminations, or protect interior mechanisms (e.g. delicate integrated electrical fittings) from structural stress and/or potential physical, thermal, chemical, biological or radiational damages from the surrounding environment. Housing may also be the body of a device, vital to its function.

In structural engineering, deflection is the degree to which a part of a long structural element (such as beam) is deformed laterally (in the direction transverse to its longitudinal axis) under a load. It may be quantified in terms of an angle (angular displacement) or a distance (linear displacement).A longitudinal deformation (in the direction of the axis) is called elongation.

The deflection distance of a member under a load can be calculated by integrating the function that mathematically describes the slope of the deflected shape of the member under that load. Standard formulas exist for the deflection of common beam configurations and load cases at discrete locations.Otherwise methods such as virtual work, direct integration, Castigliano's method, Macaulay's method or the direct stiffness method are used. The deflection of beam elements is usually calculated on the basis of the Euler–Bernoulli beam equation while that of a plate or shell element is calculated using plate or shell theory.

A mullion is a vertical element that forms a division between units of a window or screen, or is used decoratively. When dividing adjacent window units its primary purpose is a rigid support to the glazing of the window. Its secondary purpose is to provide structural support to an arch or lintel above the window opening. Horizontal elements separating the head of a door from a window above are called transoms.

The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a hydrodynamic and counterbalancing purpose as well. The laying of the keel is often the initial step in constructing a ship. In the British and American shipbuilding traditions, this event marks the beginning date of a ship's construction.

Machine element or hardware refers to an elementary component of a machine. These elements consist of three basic types:

1. structural components such as frame members, bearings, axles, splines, fasteners, seals, and lubricants,
2. mechanisms that control movement in various ways such as gear trains, belt or chain drives, linkages, cam and follower systems, including brakes and clutches, and
3. control components such as buttons, switches, indicators, sensors, actuators and computer controllers.

While generally not considered to be a machine element, the shape, texture and color of covers are an important part of a machine that provide a styling and operational interface between the mechanical components of a machine and its users.

A cantilever is a structural element that is firmly attached to a fixed structure at one end and is unsupported at the other end. Sometimes it projects from a vertical surface such as a wall. A cantilever can be in the form of a beam, plate, truss, or slab.

When subjected to a structural load at its far, unsupported end, the cantilever carries the load to the support where it applies a shear stress and a bending moment.

In solid mechanics, a bending moment is the reaction induced in a structural element when an external force or moment is applied to the element, causing the element to bend. The most common or simplest structural element subjected to bending moments is the beam. The diagram shows a beam which is simply supported (free to rotate and therefore lacking bending moments) at both ends; the ends can only react to the shear loads. Other beams can have both ends fixed (known as encastre beam); therefore each end support has both bending moments and shear reaction loads. Beams can also have one end fixed and one end simply supported. The simplest type of beam is the cantilever, which is fixed at one end and is free at the other end (neither simple nor fixed). In reality, beam supports are usually neither absolutely fixed nor absolutely rotating freely.

The internal reaction loads in a cross-section of the structural element can be resolved into a resultant force and a resultant couple. For equilibrium, the moment created by external forces/moments must be balanced by the couple induced by the internal loads. The resultant internal couple is called the bending moment while the resultant internal force is called the shear force (if it is along the plane of element) or the normal force (if it is transverse to the plane of the element). Normal force is also termed as axial force.

A deck is the surface of a bridge. A structural element of its superstructure, it may be constructed of concrete, steel, open grating, or wood. Sometimes the deck is covered by a railroad bed and track, asphalt concrete, or other form of pavement for ease of vehicle crossing. A concrete deck may be an integral part of the bridge structure (T-beam or double tee structure) or it may be supported with I-beams or steel girders.

When a bridge deck is installed in a through truss, it is sometimes called a floor system. A suspended bridge deck will be suspended from the main structural elements on a suspension or arch bridge. On some bridges, such as a tied-arch or a cable-stayed, the deck is a primary structural element, carrying tension or compression to support the span.

In structural engineering, a trestle support (or simply trestle) is a structural element with rigid beams forming the equal sides of two parallel isosceles triangles, joined at their apices by a plank or beam. Sometimes additional rungs are stretched between the two beams. A pair of trestle legs can support one or several boards or planks, forming a trestle table or trestle desk. A network of trestle supports can serve as the framework for a trestle bridge, and a trestle of appropriate size to hold wood for sawing is known as a sawhorse.