Remember I am not an expert in FreeCAD geometry modelling, however since I am beginning I think I will stumble upon many of the difficulties that new comers will find.

One of my geometries presented a challenge and thus I would like to discuss with the community to figure out what is wrong with it and what are the typical errors those problems can generate.

The geometry is a sunbech structure, those types that we can relax by the pool

Going direct to the case:

- Can mesh with NetGen

- Can't mesh with Gmsh

- Can't solve with Calculix

The FreeCAD example is in attach on the following link:

https://we.tl/z3T2N5Rayt

My guess is that these are bad elements either from the beginning or due to excessive deformation.

How would you troubleshoot this issue?acobian determinant in element 311025

What can I do to make the solid work with gmsh?

How do I locate the bad elements on my solid?

How can I avoid the bad geometry from when I am building the CAD model?

Any help is much appreciated.

I checked the geometry:

SunBenchPartial2.Fusion002:

VERTEX : 56

EDGE : 84

WIRE : 44

FACE : 36

SHELL : 3

SOLID : 1

COMPSOLID : 0

COMPOUND : 1

SHAPE : 225

Calculix gives some feedback:

0.0: Check dependencies... 108.3: Write completed. 0.0: CalculiX binary: /usr/local/Cellar/calculix-ccx/2.12/bin/ccx_2.12 0.0: Run CalculiX... 0.1: Starting CalculiX... 0.2: CalculiX is running... 28.2: CalculiX stopped. 28.3: ************************************************************ CalculiX Version 2.12, Copyright(C) 1998-2015 Guido Dhondt CalculiX comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it under certain conditions, see gpl.htm ************************************************************ You are using an executable made on Tue Jul 4 17:04:04 BST 2017 The numbers below are estimated upper bounds number of: nodes: 424365 elements: 361926 one-dimensional elements: 0 two-dimensional elements: 0 integration points per element: 4 degrees of freedom per node: 3 layers per element: 1 distributed facial loads: 0 distributed volumetric loads: 0 concentrated loads: 83224 single point constraints: 204 multiple point constraints: 1 terms in all multiple point constraints: 1 tie constraints: 0 dependent nodes tied by cyclic constraints: 0 dependent nodes in pre-tension constraints: 0 sets: 5 terms in all sets: 1492583 materials: 1 constants per material and temperature: 2 temperature points per material: 1 plastic data points per material: 0 orientations: 0 amplitudes: 2 data points in all amplitudes: 2 print requests: 2 transformations: 0 property cards: 0 *INFO reading *STEP: nonlinear geometric effects are turned on *WARNING reading *STATIC: a nonlinear analysis is requested but no time increment nor step is specified the defaults (1,1) are used STEP 1 Static analysis was selected Newton-Raphson iterative procedure is active Nonlinear geometric effects are taken into account Decascading the MPC's Determining the structure of the matrix: number of equations 1272891 number of nonzero lower triangular matrix elements 43464747 increment 1 attempt 1 increment size= 1.000000e+00 sum of previous increments=0.000000e+00 actual step time=1.000000e+00 actual total time=1.000000e+00 iteration 1 Using up to 1 cpu(s) for the stress calculation. Using up to 1 cpu(s) for the symmetric stiffness/mass contributions. *ERROR in e_c3d: nonpositive jacobian determinant in element 153031 *ERROR in e_c3d: nonpositive jacobian determinant in element 157660 *ERROR in e_c3d: nonpositive jacobian determinant in element 166063 *ERROR in e_c3d: nonpositive jacobian determinant in element 205046 *ERROR in e_c3d: nonpositive jacobian determinant in element 219980 *ERROR in e_c3d: nonpositive jacobian determinant in element 262854 *ERROR in e_c3d: nonpositive jacobian determinant in element 278807 *ERROR in e_c3d: nonpositive jacobian determinant in element 284306 *ERROR in e_c3d: nonpositive jacobian determinant in element 287731 *ERROR in e_c3d: nonpositive jacobian determinant in element 287812 *ERROR in e_c3d: nonpositive jacobian determinant in element 287822 *ERROR in e_c3d: nonpositive jacobian determinant in element 311025 *ERROR in e_c3d: nonpositive jacobian determinant in element 313616 *ERROR in e_c3d: nonpositive jacobian determinant in element 338044 *ERROR in e_c3d: nonpositive jacobian determinant in element 338371 *ERROR in e_c3d: nonpositive jacobian determinant in element 343540 28.3: CalculiX done! 28.3: Loading result sets...