Transition Zone NTRANS
\nWhen the entire surface or edge of a system is not a design zone and both design and non-design regions exist adjacent to one another, a transition zone can be defined using NTRANS which helps to smooth out the transition. Sharp changes can occur in the design region during optimization and the sections of the design region closest to the non-design region are designated as a transition zone where the corresponding location of the adjacent non-design region is taken into consideration allowing for a smoother transition from the design to non-design region. NTRANS defines the number of design grid layers in the transition zone to non-design area, where additional treatment will be applied to produce smooth transition.
\nNTRANS = 3<\/p>\n
Side Constraints
\nSide constraints allow the deformation space to be defined as a coordinate range. Similar to the maximum shrinkage and growth parameters as defined on the PERT continuation line, it is possible to limit the extent of the total deformation of the design region by way of side constraints. Side constraints allow the deformation space to be defined as a coordinate range; that is, between (x1, y1, z1) and (x2, y2, z2). These ranges may be with reference to rectangular, cylindrical or spherical systems. <\/p>\n
Move Factor MVFACTOR
\nThe maximum allowable movement in one iteration of the grids defining a free-shape design region is specified as: MVFACTOR * mesh_size. The default value of MVFACTOR is 0.5. A smaller MVFACTOR will make free-shape optimization run slower but with more stability. Conversely, a larger MVFACTOR will make free-shape optimization run faster but with less stability.<\/p>\n
Number of Layers for Mesh Smoothing NSMOOTH
\nWith free-shape optimization, internal grids adjacent to those grids defining the design region are moved to avoid mesh distortion. The number of layers of grids to be included in the mesh smoothing buffer may be defined by the NSMOOTH field on the PERT continuation line of the DSHAPE entry. The default value of NSMOOTH is 10. A larger NSMOOTH will give a larger smoothing buffer, and consequently will work better in avoiding mesh distortion; however, it will result in a slower optimization.<\/p>\n","protected":false},"excerpt":{"rendered":"
Transition Zone NTRANS When the entire surface or edge of a system is not a design zone and both design and non-design regions exist adjacent to one another, a transition zone can be defined using NTRANS which helps to smooth out the transition. Sharp changes can occur in the design region during optimization and the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","_lmt_disableupdate":"yes","_lmt_disable":"","jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[24,27],"tags":[],"class_list":["post-1975","post","type-post","status-publish","format-standard","hentry","category-hypermesh","category-tcl"],"modified_by":"gantovnik","jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8bH0k-vR","jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":536,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/05\/optistruct-during-topology-optimization-can-i-use-stress-constraints-through-dresp1-in-the-design-space\/","url_meta":{"origin":1975,"position":0},"title":"OptiStruct: During topology optimization, can I use stress constraints through DRESP1 in the design space?","author":"gantovnik","date":"2020-05-09","format":false,"excerpt":"OptiStruct: During topology optimization, can I use stress constraints through DRESP1 in the design space? Defining local stress constraints through DRESP1 in the design region for Topology Optimization is allowed. The Stress-Norm method is used to aggregate stress responses.","rel":"","context":"In "HyperMesh"","block_context":{"text":"HyperMesh","link":"https:\/\/gantovnik.com\/bio-tips\/category\/hypermesh\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":539,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/05\/optistruct-can-i-use-buckling-constraints-on-a-topology-or-free-size-optimization\/","url_meta":{"origin":1975,"position":1},"title":"OptiStruct: Can I use buckling constraints on a topology or free-size optimization?","author":"gantovnik","date":"2020-05-09","format":false,"excerpt":"OptiStruct: Can I use buckling constraints on a topology or free-size optimization? There are several barriers for buckling constraints in topology optimization: Buckling constraints are conditional, similar to stress constraints (see Can I use stress constraints with topology or free-size optimization?). Structural instability does not exist when structural parts vanish.\u2026","rel":"","context":"In "HyperMesh"","block_context":{"text":"HyperMesh","link":"https:\/\/gantovnik.com\/bio-tips\/category\/hypermesh\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1827,"url":"https:\/\/gantovnik.com\/bio-tips\/2023\/04\/344-failsafe-topology-optimization\/","url_meta":{"origin":1975,"position":2},"title":"#344 Failsafe topology optimization","author":"gantovnik","date":"2023-04-20","format":false,"excerpt":"Failsafe topology optimization: FSO divides the structure into damage zones and generates multiple models (equal to the number of failure zones). Each model is the same as the original model minus one failure zone. In this process, the FSO method is applied by running Topology Optimization simultaneously for all such\u2026","rel":"","context":"In "HyperMesh"","block_context":{"text":"HyperMesh","link":"https:\/\/gantovnik.com\/bio-tips\/category\/hypermesh\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":684,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/09\/119-sol200-why-is-scaling-important-in-optimization\/","url_meta":{"origin":1975,"position":3},"title":"#119: SOL200 – Why is Scaling Important in Optimization?","author":"gantovnik","date":"2020-09-28","format":false,"excerpt":"#118: SOL200 - Why is Scaling Important in Optimization? When performing an optimization analysis, it is not unusual to have many constraints and\/or design variables that have large differences in magnitudes. If these values are used without scaling, some constraints and\/or design variables may dominate. In some cases, the convergence\u2026","rel":"","context":"In "nastran"","block_context":{"text":"nastran","link":"https:\/\/gantovnik.com\/bio-tips\/category\/nastran\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":541,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/05\/doptprm-discrete\/","url_meta":{"origin":1975,"position":4},"title":"DOPTPRM, DISCRETE","author":"gantovnik","date":"2020-05-11","format":false,"excerpt":"DOPTPRM, DISCRETE Bulk Data Entry Discreteness parameter. Influences the tendency for elements in a topology optimization to converge to a material density of 0 or 1. Default DISCRETE=1. Recommended bounds are 0.0 and 2.0 for shells, or 3.0 for solids. Improving Discreteness. There are numerous ways to improve the discreteness\u2026","rel":"","context":"In "HyperMesh"","block_context":{"text":"HyperMesh","link":"https:\/\/gantovnik.com\/bio-tips\/category\/hypermesh\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":2146,"url":"https:\/\/gantovnik.com\/bio-tips\/2024\/04\/418-some-comments-about-exclude-command-in-linear-buckling-analysis-using-optistruct\/","url_meta":{"origin":1975,"position":5},"title":"#418 Some comments about EXCLUDE command in Linear Buckling Analysis using OptiStruct","author":"gantovnik","date":"2024-04-10","format":false,"excerpt":"The EXCLUDE command can be used to select a set of elements to be excluded from a Linear Buckling Analysis. EXCLUDE = ESID (ESID is Set identification number of an element set) The excluded elements are only removed from the geometric stiffness matrix, resulting in a Buckling Analysis with elastic\u2026","rel":"","context":"In "HyperMesh"","block_context":{"text":"HyperMesh","link":"https:\/\/gantovnik.com\/bio-tips\/category\/hypermesh\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/posts\/1975","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/comments?post=1975"}],"version-history":[{"count":0,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/posts\/1975\/revisions"}],"wp:attachment":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/media?parent=1975"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/categories?post=1975"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/tags?post=1975"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}