I came across an interesting application last week. While walking up and down a metal staircase we often do not pay attention to vibration effects. Maybe the engineer working on the project figured this out for us. If that was not the case, I would feel extremely unsecure walking up and down the staircase. Imagine all the vibrations running through you …I think I would turn around and exit the building.
So my colleague modeled a staircase to test if SOLIDWORKS Simulation can be of use. I assumed kids were standing at three different locations to be my test case. The good thing about using Dynamic analysis in SOLIDWORKS Simulation is it gives me resonant frequencies.
So given the load, the frequency range of concern is from 31 Hz to 271 Hz. I will now create a Dynamic test that runs through this range and helps me figure out if resonance would take place. In addition, I can figure out the stress and deformation at a particular resonant frequency.
Once I have this range, I can then pick any location and study the maximum possible deformation at a particular excitation. Now that I know the max deformation of ~ 0.013” occurs at 32 Hz, I need to figure out the possibility of a person exciting this frequency. It turns out the average person walks at 3 mph, and this is way slower than exciting 32Hz. So it turns out, this stair designs was safe after all. Having the ability to get detailed results and easy charts to complete the picture helps understand the design issue.
SOLIDWORKS Simulation provides detailed vibration data through frequency analysis and dynamic analysis to ensure product performance and safety. Vibration analysis is an important consideration when an applied load is not constant (static), inducing unstable modes of vibration (resonance) which result in a shortened service life and cause unexpected failures.