Computer models are useful in structural analysis, but are no substitute for laboratory testing. An important facet of structural testing and design, field and laboratory evaluation of engineering materials provides invaluable design and forensic information for structural engineers.
In this age of computer modeling and analysis one might begin to think that structural testing of engineering designs and materials is soon to become a thing of the past. Reams of tabulated data on material properties, limits of failure, safety factors, and other pertinent information already exist, so why bother with the trouble and expense of performing actual tests? Aren’t field testing laboratories for construction and civil engineering getting anachronistic? No. Raw materials are never consistent, construction and manufacturing processes are never perfect, and structural requirements constantly change with new applications, designs, and desired functionality. For these reasons, field and laboratory structural analysis, engineering design and testing, and materials engineering and testing will continue for as long as there is a need for structural engineering
Structural testing is performed as a means to investigate the performance of materials, assemblies, and designs utilized in civil engineering and mechanical engineering projects. The engineering laboratory testing of materials can evaluate structural components for various physical properties such as response to stress, strain, and loads under a variety of conditions such as varying temperature and accelerated environmental aging. Fatigue cracking, shear flows, compressive and tensile load failures, strain response, elastic and viscous behaviors, sound and vibration dampening, combustion resistance, impact characteristics, creep, and ductility are some of the typical analyses performed. A structural testing laboratory can also analyze assemblies of engineering materials for expected and maximum response under static and cyclic loading, identify unexpected load distribution and/or response, determine the strength of connections (such as pull out resistance of fasteners, welding joints, etc.), gauge wind resistance and airflow characteristics, seismic response, racking characteristics of panels and assemblies, beam and truss load response, airframe resilience, forensic analysis, and so on. These analyses help pinpoint structural weaknesses and verify design safety factors that can help acquire the structural engineer’s stamp of approval, or help the forensic structural engineer determine cause of failure.
And testing is not limited to laboratory facilities. Field testing laboratories for construction and civil engineering perform special inspections for foundations, concrete cure, anchoring adhesives and connections, welding joints, presence of specified structural elements such as high strength fasteners, structural steel assemblies, and other critical design elements required for the safe performance of civil engineering structures. Field testing is not limited to civil applications but can also be conducted for mechanical structural testing as well. By installing load cells, strain gauges, and various other transducers and sensors the response of automobile and aircraft frames, for example, can be ascertained under actual usage conditions. Impact analysis of these structures is an especially active field as part of an ongoing effort to improve the protection of the occupants during accidents, crashes, and explosive events.