Spatially varied pressure load

I’m trying to analyze stresses in a container holding water with a free water surface. To do that, I need to specify spatially varied pressures on faces of the container. I haven’t found a simple way to do that in Calculix but maybe I’ve missed a loading option. While my case is a simple ‘hydraulic’ load, there are many other cases where spatial variation of pressure or load are common.

Your guidance and suggestions would be appreciated.

even many commercial FEA provide for such a feature, i still prefer using manual approach to avoidance of doubt since definition has two dependencies: height at zero pressure and base position (highest pressure). problem comes when the models contains many tank at different position and elevation.

try make a structured mesh if your model are simple enough or using partition for complex model, split by eight segment along height and refined if necessary. then apply uniform pressure (averaging of linear interpolation) for each segmented layer of wall height. this approach should be no significant discrepancy compared to user defined subroutine dload.f of PxNUy in CalculiX.