Physics Of The World Trade Center

2217 Words9 Pages
Introduction The World Trade Center was a global icon of The United States of America. The tallest of the buildings was over 1,300 feet high (10). With such large buildings, the materials used in construction needed to meet certain standards just to successfully stand erect. The design intent has the biggest factor for the material selection. In the World Trade Centers, the materials were supposed to meet certain properties and requirements. The analysis of whether or not the World Trade Center buildings were built to requirements will be discussed. Analysis ● Mechanical properties ○ Tensile testing Tensile testing is important in order to determine the strength of the beams from the world trade centers. The strength needs to be high in…show more content…
Next, it was found to be true that the measured strength typically was greater than the specified strength, which indicates that the factor of safety is met (8). However, some tests have measured strengths less than the specified strength (8). Figure 1 displays the factor of safety in each region of the towers. Anything with a R-value less than 1, had a yield strength less than the specified requirements. Due to this, the part is not classified as defective, but is a form of quality control (8). This is important because each area of the building needed to be inspected to ensure that there were no specific regions of failure. The parts of lower strengths have been analyzed and it has been determined that they had no contribution to the failure of the buildings (8). The factors of safety were generally met. Figure 1: R measurement versus specified yield strength (8) ○ Ductility Having a ductile fracture rather than a brittle fracture is important. A ductile fracture is able to absorb more energy than a brittle fracture can (8). Figure 2 shows the relationship between brittle and ductile metals and their fracture points in a stress/strain diagram. A brittle fracture can withstand more stress, but only when lower strains are applied. A ductile fracture can withstand less stress, but can withstand more strain. This figure illustrates this relationship
Open Document