Comparison between mathematical and model analysis of stresses in building frames

Abstract

The first experiment consisted of the making and testing of a cardboard model of a beam fixed at both ends. The results obtained from the model compared very favorably with the mathematical solution as there was a variation of only 1.8 percent.

The second experiment was performed with a cardboard model of a bent fixed at both supports. The results from the model as compared to the mathematical solution could not be made to check very closely. There was a variation up to 10 percent in the influence lines for moment for horizontal loads, and a difference as high as 50 percent for vertical loads.

It was found after the experiment was performed that the modulus of elasticity of the columns was about four times as great as the modulus in the girder. Then after making the correction in the mathematical solution for the difference in the modulus of elasticity there were only three points that showed a variation of over six percent, and most of the points were under 3½ percent.