Description
Structural engineering involves the analysis and design of structures and is one of the core sub-disciplines of civil engineering. Civil engineering structures take a variety of forms and include buildings, bridges, towers, marine structures, dams, tunnels, retaining walls and other infrastructure. The most common materials used for the construction of these structures are concrete, steel and timber, although a variety of other materials are used including stone, aluminium, polymers, carbon fibre, glass and many more.
Structural engineering underpins and sustains the built environment, where bridges, buildings and other structures must be safe, serviceable, durable, aesthetically pleasing and economical. It is concerned primarily in developing structural solutions to resist loads and other forces, and in devising ways to provide safe load paths for these forces. It is an applied science, founded on mathematical laws and physical concepts applied to engineering mate-rials, both traditional and advanced, for the provision of infrastructure and technological innovation. The demands of new and existing structures imposed by society and by economics and the use of new or advanced materials require solutions that challenge and unite creativity and scientific rigour.
Structural design involves the determination of the type of structure that is suitable for a particular purpose, the materials from which the structure is to be constructed, the loads and other actions that the structure must sustain and the arrangement, layout and dimen-sions of the various components of the structure. This involves detailed calculations to ensure that the structure is stable and that every structural member, and every connection between members, has adequate strength to resist the design loads. It also involves determination of the deformation of each part of the structure to ensure that the structure remains serviceable throughout its design life and is able to perform its intended function. Structural design involves careful detailing of every part of the structure, including the preparation of detailed structural drawings that effectively communicate the engineering design to the contractors who are engaged to build the structure.
Structural analysis is an integral part of structural design. It involves the calculation of the response of the structure to the design loads and imposed deformations that it will be required to resist during its lifetime. This involves the determination of the internal forces within the various components of the structure and the deformation of these components. Calculation of the internal forces in a structure will allow the structural designer to select materials and member sizes that provide the structure with adequate strength and ensure that the chances of collapse are acceptably small. Calculation of the deformation of the structure will permit the assessment of serviceability. Whether or not a structure is accept-able for a particular purpose depends on its deformation, as well as its strength.
The mathematical algorithms used for structural analysis range from classical methods, suitable for manual calculation (often assuming linear elastic material behaviour), to more complex non-linear numerical analysis, using modern matrix methods and high-performance computers. The choice depends on the type and complexity of the structure and the computational power available to the structural analyst. All methods involve the application of structural mechanics to an idealised structure, where approximations are made concerning the geometry of the structure and its support conditions, the applied loads and deformations, and the material modelling laws. The interpretation of the results of the analysis requires both experience and engineering judgment.