More than 20 years of experience makes ixForten 4000 one of the most complete solutions in the field of tensile structure engineering ixForten 4000 Structural Analysis is based on a non-linear FEA kernel accurate and relaiable. Our FEM engine is second to None and not only for membrane structures but also for conventional steel ,concrete and wood buildings. FEM library : 2 node membrane link ( special element for membrane FDM meshes) : only tension 2 node cable : only tension - non-linear 2 node truss ( pin jointed element ) : tension ,compression - linear and non-linear 2 node gap : only compression - non-linear 2 node beam element : linear & non-linear behaviour , axial,shear,bending stiffness (Reissner-Timoshenko theory) 3-4 node membrane element : in plane stress element - linear and non-linear 3-4 node plate shell element : plane stress & bending stiffness (Reissner-Mindlin theory) - linear and nonlinear Axial force plot after non-linear analysis