Structural & Thermal

Structural & Thermal

Why are moment probe calculations scoped to contact so far off when large deflection is turned ON?

    • FAQFAQ
      Participant

      For those Moment probes which perform a moment arm calculation, Mechanical employs the undisplaced mesh. In other words, when Mechanical computes a moment arm for a node, it finds the difference between the (x,y,z) of the node and the summation point (sx,sy,sz) in the base mesh: moment_arm = (x,y,z) – (sx,sy,sz) Note that the above formula differs from how Mechanical APDL performs a moment arm calculation and therefore, the results between the two applications differ. Mechanical APDL uses the FSUM command for large scale deformation analyses (NLGEOM,ON). In Mechanical APDL, node-based displacements, where the NLGEOM,ON command is issued, are added to the (x,y,z) in the base mesh, such that: moment_arm = (x+ux,y+uy,z+uz) – (sx,sy,sz)