Material properties: effect on deflection, rotation and vibration - Part 1

摘要

Over the past 20 years, structural engineering has been subjected to greater demands due to a wider variety of materials in use, and the necessity to construct in a sustainable manner in order to obtain more energy-efficient buildings. Furthermore, when more than one material is in use, shrinkage problems become more evident, while differential corrosion of different metals in contact with each other has to be ascertained. Spans are getting longer, while new, advanced structural material is becoming lighter. It is therefore not surprising that the effect of cracking in building materials due to deflection effects, together with the problem of vibrations onto structural floors, is increasing. Some idea of this transition can be obtained by noting that whereas the sway in a strong wind of the Empire State Building is limited to 100mm, the sway of modern skyscrapers may be as high as 1000mm.