Hi, I am trying to setup boundary conditions on a quarter section of a symmetric steel sub-frame for a cast iron boiler. My application is I'm conducting a stress analysis on the sub frame by measuring strain with strain gauges. The strain gauges are placed close and far away on the top of a hollow box channel beam from a c-channel welded to the top of the boxed beam. the strain is measured when a forklift lifts the frame and boiler off the ground through the c-channels on the bottom of the frame to an equilibrium position. I am trying to obtain a psi stress value at these particular points where the strain gauges are mounted using Simulation in Solidworks. I am having trouble setting up my boundary conditions properly to achieve a model that mimics this analysis. I tried placing a uniformly distributed load equal to 1/4 of the weight of the cast iron boiler resting on the top beam of the sub-frame, as well an upward force greater than the weight of the boiler and frame on the inside face of the steel c-channel that is being lifted by the forklift. As far as the fixtures are concerned, I was told any face that was cut I had to fix in the normal direction to the face. My results have not shown stress concentrations where I expect them to be and I wondering how i can improve my Simulation study. My model is attached, Thanks!