11 Replies Latest reply on May 19, 2011 9:09 PM by Dougal Hiscock

    Wheel Weight loadings of a truck

    Chris Peters

      Hey All

       

      We're working on layout some cargo on a flat bed truck. Was wondering if there is a quick way to be able to move the cargo around and see how the position off the mass effects the loading on each wheel individually?

       

      I assume we can do this with sensors or something similar? Also can this be done in standard Solidworks or just premium?

       

      Cheers

       

      Chris

        • Re: Wheel Weight loadings of a truck
          Karan Lingerkar

          Chris,

           

          I am supposing that only a static FEA stress analysis will address your concerns, if I am understanding correctly what you exactly need (if you are looking for wheel deformations when you load the mass on the truck). You can change positions of cargos my defining various model configuratuions (using mates) and performing FEA on each of the configurations seperately and finally make an excel graph to see the effect of change of center of mass of the cargo on the stress on the wheels.

           

          Hope this helps. Thanks!

          • Re: Wheel Weight loadings of a truck
            John Sutherland

            Probably the quickest way is to calculate it with high school math, but if your objective is to learn SW then follow Karen's advice.

            • Re: Wheel Weight loadings of a truck
              Chris Peters

              Yes I know this is fairly simple manual calculation however we need the model to give to people who dont know how to do the calculations,  I don't need deformation of the wheels. All I need is to be able to move the weights around and see how the weight is distributed over the 4 wheels so we can make sure we are not overloading one axle.  There's got to be a quick simple way to do this.

              • Re: Wheel Weight loadings of a truck
                Chris Peters

                It doesn't have to be super accurate. Were talking about having roughly 6, 150-300Kg box being placed in specific areas of a van so if it's out by a few Kg's its not the end of the world.

                 

                Can I just model a flat platform with sensors in each of the 4 corner and as I move the boxes around I re-run the simulation and it tells me the weight/force on each of the four sensors?

                  • Re: Wheel Weight loadings of a truck
                    Dougal Hiscock

                    You won't get it within a few kg's or even close.  Trying to calculate (or even measure) the changing weight on four wheels of a vehicle is difficult because it depends on the stiffness of the tyres, stiffness of the suspension and rigidity of the chassis.  Basically the softer and more flexible everything is, the more it load-shares across the different contact points.  Only if everything is perfectly rigid and perfectly flat will calculations give you the answer you expect.

                     

                    To get a perfect result isn't going to be possible, to get an acceptable result will depend how much time and money you want to throw at it.

                     

                    It's not a problem that's really suited to FEA style analysis, it's a problem best attacked by spreadsheets and good old fashioned maths.  Possibly automated with VB.

                  • Re: Wheel Weight loadings of a truck
                    Chris Peters

                    So your telling me I can't have a flat plate, put some objects on top of varying weights and let solidworks tell me the weight distribution on the four corners of the plate, assuming everything is static and solid? I am sure it can work out something as simple as this, even without simulation????

                      • Re: Wheel Weight loadings of a truck
                        Dougal Hiscock

                        The problem is "statically indeterminate".  Which means you can't solve it without knowing the stiffness of the plate and it's four supports.  The plate in this case is a truck chassis, the supports are pneumatic tyres mounted on springs.  All flex enough to visibly deflect.

                         

                        If you were to simplify the problem to 3 supports then it can be solved without knowing stiffness.  But your truck doesn't have 3 wheels.