For the team to decide on a material we need to know which criteria need to be met. The design involves a large beam that will take the majority of the load and will be supported by cables and smaller beams. In some cases the calculations can be made and a suitable material can be found, or the type of beam can be used with a single material chosen first. As the material specialist has not been available to aid this decision the team have worked together and decided on plain carbon steel for the build. Plain carbon steel is a very versatile and cost effective material. We can reduce the size of the beams without compromising strength and hence reduce weight.
To carry out the initial stress analysis I have used SolidWorks, however, the loads have been exaggerated to account for material defects, modelling errors and over working. The results show that the main beam will take the load with a stress of 220.59GPa where the yield stress of steel is about 280GPa. The final design will have support beams and cables so the maximum experienced stress will be noticeably smaller.
Final testing will be carried out by Onwell, the design engineer.
After testing various beam types and size from the SolidWorks ‘Toolbox’, this beam (dimensions below, found on http://www.franklinsteelplc.co.uk/steel/unibeam.htm) is the best suited for the task.
Are you sure about the stresses ?
ReplyDeleteThe yield stress of a typical mild steel is 280 MPa not GPa.