In relation to the presence or absence of ductility in bending joints of steel structures

In relation to the presence or absence of ductility in bending joints of steel structures

Second part:
If the steel was not inherently flexible, another design model would have to be used. But glass is an inherently brittle material. My guess is that its flexural strength is limited to the tensile stress that develops on the outer surface, which will include defects, flaws or cracks. These defects reduce the strength of the glass by more than 100 compared to the pure strength of the glass – again, because the glass is unable to create sites to redistribute the stresses at the site of these defects and fractures. (In addition, such defects also exist in steel, but steel can accommodate the presence of natural defects that are usually produced in the manufacturing process.) Glass failure is also sudden, because glass cannot be permanently supported by the load. change shape For these reasons, my opinion is that glass is designed for higher safety factors than steel. I imagine this is an attempt to ensure that the design loads are not exceeded. The interesting thing is that when the factors that are developed for safety are not measured (and maybe not measured) it is human error. Therefore, I suspect that the analysis methods used for glass are also different from those used for steel – in addition, the likelihood of exceeding the design loads is reduced. Although steel is inherently flexible, there are limits to its malleability. When a structure is expected to remain nominally elastic, its ductility demand will be relatively small. However, under certain (or essentially unpredictable) events, the ductility demand can be very high. In such cases (designing for severe earthquakes and preventing progressive failure) yielding is encouraged in the member and non-yielding is encouraged in the joints through the use of higher assumed loads, such as the expected resistance, this is similar to the use of Higher safety factors for glass design. Safety in the design of glass is also the reason that the connection is not subjected to more forces than the demands of the design assumption. Such cases are sometimes described as force-controlled, and no special ductility demands apply to force-controlled members. However, even force-controlled elements have some degree of ductility, and this ductility may be called upon by the structure at the service level. continues
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This post is written by MOJTABA_SHIRI