Week 8-Challenge

objective - 3D meshing of the given housing model having :-

                  minimum element size - 2mm

                  maximum element size -7mm

                  target element size      - 5mm

                  tet collapse                 - 0.15mm

         Also, 3D meshing for the given model-2 and model-4 having

                  target element size      - 6mm

procedure - In the first step imported the housing model as stp file in the hypermesh window.

           picture representing the imported housing model in hypermesh

. In the next step as this model has one solid component inside so creating another component      named as component 1 in component tree and segregated the solid component from the              surface component by using the organise option under the tools page.

      pictures representing the segregation of solid part organised as component

. In the next step selected the surface component as current component and done some   geometric cleanup on this surface model like toggeled some lines where element of length 5mm   cannot be meshed.

       picture reprsenting the toggled lines which are not adequate for target element             size

. In the next step did 2d meshing on this component by selecting elemnent type as trias only     and having element size of 5mm.

      picture representing the shell mesh of trias element having 5mm of element size

 . In the next step under the quality criteria under the 2D panel checked the minimum length       and maximum length as 2mm and 7mm respectively for these shell elements. many elements   breaching the quality criteria so used hit and trial method without fixing it converted these 2D   shell elements into 3D tetramesh under the 3D page.

       picture representing scrutunizing the quality criteria for the shell elements

        picture representing the conversion of shell elements into 3D tetramesh

. In the next step under the check elements option selected the 3D option and hit on the tet   collapse option which represents the height of the tetra elements.very few elements breaching   the quality criteria of this 3D mesh.

    picture representing the examining of tet collapse for the 3d tetra elements

. In the next step used node distance option to fix these elements that was breaching the given   tet collapse value.

  picture representing the node distance option to fix the elements that disobeying the   tet collapse value.

    picture representing the tet collapse value become zero after remeshing and using        the node distance option.

 

                           picture representing the solid component

. In the next step under the 3D page selected the volume tetra and selected the solid   component  to get the 3D tetra mesh.

    picture representing the volume tetra mesh of the solid component

. In the next step under the check elements in the 3d panel checked the tet collapse and every   element passed the quality criteria.

           picture representing the visualisation of quality criteria for volume tetramesh

. In the next step imorted the model-4 .hm file given in the challange.

                                picture representing the model-4 .hm file

. In the next step analysed the model under wireframe mode and model were opened at certain   areas i.e there were red lines at certain areas for this model so to fix this used the toggled   option under quick edit menu.

  picture representing the red lines at certain area of this model under wireframe mode

   picture representing the fixing of open areas i.e red lines using the toggle edge               option

. In the next step applied the quick tetramesh under the utility tab on this model and set the   mesh size as  6mm and selected the element type as trias only.

                         pictures representing the quick tetramesh on this model

. In the next step checked the tet collapse quality criteria for these elements where large number   of elements were breaching the quality criteria. To fix this remeshed these elements using the   tetra remesh option under the 3d page and set the tetramesh parameters for this remesh.

            picture representing the tetramesh parameters as required

           pictures representing the tetra remesh done the quick tetramesh

. In the next step checked the tet collapse quality paramater for this remeshed mesh and zero   elements were failing i.e every element passed the quality criteria.

              picture representing the element passed the quality criteria  

. In the next step imported the chasis assembly .hm file in the hypermesh window.

               picture representing the imported chasis file in the hypermesh 

. In the next step hided all the components except the hub component and deleted the solids for    this component and done some geometric cleanup like toggled the sharped edges as well as the    deleted the surface fillets below 5mm and deleted the tooth or gears present inside the                component.

           picture representing the deleted solids of the hub component

   picture reprsenting the toggled sharp edges and the lines wahich were less than             6mm apart

     picture representing the deleted surface edges which were not adequate for                   meshing and also deletion of teeth or gears inside the hub 

. Now the geometric is ready for mesh so for doing shell meshing clicked on automesh option   under 2d page and selected element type as trias only of 6mm size.

            picture representing the shell meshing on the component

. In the next step checked the minimum and maximum length quality paramters for this shell   meshing and group of elements were failing for these paramters so without fixing this directly   converted this shell mesh into 3d tetramesh and checked the tet collapse parameter of this 3d   mesh.

        picture representing the converted shell mesh into 3d tetramesh

       picture representing the analysis of tet collapse parameter on these 3d elements

. In the next step used node distance option to fix the elements that were failing.

    picture representing the node distance option to fix the failed tet collapse elements 

       picture representing the zero elements were failing for tet collapse

. In the next step opened the two solid components and directly done volume tetramesh on   these components.

      picture representing the volume tetramesh for these components

. In the next step hided these components and opened another solid component. For this  component directly doing volume tetramesh large group of elements were failing for tet collapse.so deleted the solid part of this component and done shell meshing on it and converted that shell mesh into 3d tetramesh.

                  picture representing the deleted solids of the component

.

               picture representing the converted shell mesh into 3d tetramesh

. In the last step as these components of chasis assembly were symmetric so reflected the elements of one side of 3d meshing to the other side by creating the point between them.

  picture representing reflection of elements of one side to the other side.