What is Structural Engineering?
Structural engineering may be defined as, a branch or part of civil engineering concepts, which involves design of structures (e.g. buildings, bridges,factories etc.) so that they will withstand and resist all anticipated loads and yet be economical to build.
Structural engineering is basically considered to be a branch of civil engineering, although there are some programs of study and some degrees specifically in structural engineering. The primary work done by a structural engineer consists of analyzing and designing structures. This design must be done to ensure that the structures will withstand projected loads, yet be economical to build. The projected loads may include some due to natural forces of nature and some due to applied loads put on the structure as it is being used. The natural forces of nature may include wind, snow, or possibly an earthquake, for example. The other applied loads may include, for example, equipment, furniture, people, and the weight of the structure itself. The forces or loads that the structural engineer must design for may include forces that do not change with time, called static loads, and forces that do change with time, called dynamic loads.
Structural engineers design a wide range of types of structures. Traditionally one thinks of examples such as large buildings, arenas, dams, or bridges in connection with the word structure, and in fact bridge engineering is one major category of structural engineering, but a large variety of machines, vehicles, and equipment, large and small, require structural integrity and the ability to carry specified structural loads, thus requiring design by a structural engineer. Structural engineers are also involved in the design of infrastructure such as roads, pipelines, waterways, and railroads. The structural engineer must ensure that a structure’s design satisfies any national, state, and local design codes, that it is designed for safety in its use, that it will not fail under any projected loading, and that it is designed for economical construction.
In order to be responsible for structural engineering work, it is necessary to be licensed as an engineer in most countries. Various agencies around the world have the responsibility for engineering licensing or certifying for their jurisdiction. In the United States, each state has jurisdiction for granting an engineering license to practice the profession in their particular state. In some jurisdictions, there is separate licensing for structural engineers. In other jurisdictions they may be lumped with civil engineers or simply professional engineers. In order to be eligible for licensing as a structural engineer,
civil engineer or engineer, one typically must have completed an appropriate four or five year degree program, have at least three years professional experience under the supervision of an appropriately licensed engineer, and take and pass an examination.
A structural engineer typically doesn’t work in isolation. Working together with professionals in other disciplines is usually part of the job. Other disciplines which often interact with structural engineers are architects, mechanical engineers, electrical engineers, geotechnical engineers, and environmental engineers. The structural engineer often works closely with an architect. The structural engineer must understand the architect’s plan and design, so that the structural support elements can be be placed so that they complement the design rather than interfere with it.
Structural engineers often work alongside civil engineers and architects as part of a construction team. “In a nutshell,” according to the Institution of Structural Engineers, “if a structure was a human body, then the architect would be concerned with the body shape and appearance, and the structural engineer would be concerned with the skeleton and sinews.”
Structures must be able to deal with the conditions in which they are built. A house in Canada must have a roof that can bear the weight of heavy snow and a stadium in California must be able to withstand earthquakes, for example. When building bridges, designers must take into account the conditions of terrain, wind, water and traffic volume. Structural engineers consider all of these factors and provide technical advice about the project.
“Structural engineers battle gravity, wind, snow and rain every day to provide the world with outstanding structures,” Kate Leighton, a structural engineer, said in “Careers in Structural Engineering, a publication of the Institution of Structural Engineers. “They are experts at solving problems, meeting challenges and providing creative solutions.”
Structural engineers “design roof framing (beams, rafters, joists, trusses), floor framing (floor decks, joists, beams, trusses, girders), arches, columns, braces, frames, foundations and walls,” according to the National Council of Structural Engineers Association. “In bridges, they design the deck — or riding surface, girders or stringers, and piers. The materials they use include steel, concrete, wood, masonry, andaluminum. Engineers design the structure to resist forces from gravity, earthquakes, high winds, water, soil, collisions and blast explosions.”
A structural engineer’s job includes:
● Analyzing blueprints, maps, reports, and topographical and geological data;
● Estimating the cost and quantities of materials, equipment and labor;
● Computing load and grade requirements, water flow rates and material stress factors to determine design specifications;
● Inspecting project sites to monitor progress and ensure the project is being constructed according to design specifications;
● Conducting studies of traffic patterns or environmental conditions to identify potential problems and assess how they will affect the project.
Critical skills that a person needs in structural engineering include an in-depth understanding of physics and mathematics. A structural engineer must also know the properties of various materials, such as their density, hardness, tensile strength, bulk modulus and bending strength. They need to be able to calculate how different materials will perform under stresses such as compression, tension, bending and twisting, as well as under various environmental conditions of temperature, pressure, corrosive gases and liquids, and even radiation. They also need to be able to predict how these materials will perform over an extended period of time.
Structural engineers rely increasingly on computer-aided design (CAD) systems, so proficiency with computers is essential. In addition to speeding up the drafting process, CAD systems allow for quick and easy modifications of designs and three-dimensional (3D) visualization of finished parts and assemblies.