2 Replies Latest reply on Dec 30, 2014 11:15 AM by Mike Pogue

    Distributed Mass + Gravity

    Wade Langford

      I have a static simulation of a body which has mass and has masses attached to it. To simplify the analysis, I've applied a gravity load to it to simulate it's own weight but has also applied a distributed mass to simulate the weight of the things it is supporting.

      I wish to apply a factor to all loads, I'm just wondering if I simply increase the gravity load by that factor, will this feed into the calculation of the distributed mass also or do I need to increase both the gravity load and the distributed mass by the required factor.

      To put it another way, does number entered for gravity under External Loads - Gravity also feed into the number used for gravity in the application of Distributed Mass (since you enter a kg value here rather than an N value) or does the Distributed Mass calculation simply use a base 9.81 regardless of the number in External Loads - Gravity?

       

      Thanks,

       

      Wade

        • Re: Distributed Mass + Gravity
          Wade Langford

          I think I have just discovered the answer.

          By only modifying the number in External Loads - Gravity I have arrived at around the same increase in max stress. This would therefore suggest that the factor need only be applied to the gravity and it will feed into any externally applied masses but would like that confirmed but someone more knowledgeable than I please.

            • Re: Distributed Mass + Gravity
              Mike Pogue

              Hi Wade,

               

              Force = mass * acceleration. Gravity is the acceleration in this setup. You have done it correctly by only increasing the acceleration. If you increased the mass also, you would be getting double gigged. I'd add that, assuming this is a linear study, if you analyze the design loads without adding the safety factor, you can just read the actual design safety factor right off of the results. That would save you a step.