I am modeling a small stand for an experiment at a research reactor facility. It is required to withstand seismic forces. The base of the structure is a stainless steel right-triangle shape plate. There are three small HSS "columns" at each corner and another SST plate on top of the columns. There is an "experiment" on the top plate which I will not describe for brevity. The base plate grid has 4 anchors and those are modeled as simple supports. The balance of the base plate FE grid nodes are modeled as compression only with the statements below. the problem is that I am getting X and Z shears (Y is gravity axis) and even some small tensions in these node reactions. I am at a loss...suggestions?
SPRING COMPRESSION only 31 TO 36 38 53 TO 391 393 TO 686 688 TO 842 -
844 TO 968 970 971 TO 979 KFY
SUPPORTS
31 TO 36 38 53 TO 391 393 TO 686 688 TO 842 844 TO 968 970 TO 978 -
979 ELASTIC FOOTING 5 5 DIRECT Y SUBGRADE 1000
