{"id":1558,"date":"2022-09-13T22:44:42","date_gmt":"2022-09-14T05:44:42","guid":{"rendered":"https:\/\/gantovnik.com\/bio-tips\/?p=1558"},"modified":"2022-10-11T09:34:55","modified_gmt":"2022-10-11T16:34:55","slug":"210-parametric-curve-in-3d-2-2-2-2-2-2-2-2-2-2-2-2-2-3-3-2-2-3-2","status":"publish","type":"post","link":"https:\/\/gantovnik.com\/bio-tips\/2022\/09\/210-parametric-curve-in-3d-2-2-2-2-2-2-2-2-2-2-2-2-2-3-3-2-2-3-2\/","title":{"rendered":"#301 Buckling Glossary"},"content":{"rendered":"<ul>\n<li><strong>Asymmetric buckling<\/strong>: When the structure has asymmetric geometry it may undergo stable buckling for a positive displacement parameter and unstable buckling if this displacement parameter is negative.<\/li>\n<li><strong>Bifurcation point<\/strong>: A point along a primary equilibrium path (or curve) intersected by a secondary path. Beyond this point, the primary equilibrium path becomes unstable while the secondary path emanating from this point is stable.<\/li>\n<li><strong>Buckling<\/strong>: When the elastic stiffness of the structure is canceled by the effects of compressive stress, the structure is said to buckle. In classical bifurcation buckling the effect of buckling causes the structure to suddenly displace a large amount in a direction normal to the load direction. If there is a sudden large movement in the direction of the loading, it is termed snap-through buckling.<\/li>\n<li><strong>Collapse<\/strong>: The sudden deterioration of a structure&#8217;s ability to sustain load.<\/li>\n<li><strong>Critical load<\/strong>: The load at which a structure loses stability.<\/li>\n<li><strong>Eigenvalue problem<\/strong>: Problems that require the calculation of eigenvalues and eigenvectors for their solution. Typically used for solving free vibration problems or finding buckling loads in finite element analysis.<\/li>\n<li><strong>Eigenvalues<\/strong>: The roots of the characteristic equation arising from an eigenvalue problem.<\/li>\n<li><strong>Eigenvector<\/strong>: The displacement shape corresponding to the eigenvalue.<\/li>\n<li><strong>Full Newton-Raphson method<\/strong>: A general technique for solving non-linear equations where the tangential stiffness matrix is updated at every iteration. It is often referred to as the Newton-Raphson method.<\/li>\n<li><strong>Snap-through<\/strong>: Behaviour characterized on an equilibrium curve by a limit point beyond which, under load control, the structure becomes unstable and jumps to a different deformed configuration.<\/li>\n<li><strong>Snap-back<\/strong>: This is a more severe form of snap-through instability where the structure becomes unstable and jumps to a different deformed configuration under both load and displacement control.<\/li>\n<li><strong>Yield stress<\/strong>: The stress at which plastic flow (yielding) initiates.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Asymmetric buckling: When the structure has asymmetric geometry it may undergo stable buckling for a positive displacement parameter and unstable buckling if this displacement parameter is negative. Bifurcation point: A point along a primary equilibrium path (or curve) intersected by a secondary path. Beyond this point, the primary equilibrium path becomes unstable while the secondary [&hellip;]<\/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":[2],"tags":[48],"class_list":["post-1558","post","type-post","status-publish","format-standard","hentry","category-python","tag-buckling"],"modified_by":"gantovnik","jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8bH0k-p8","jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":637,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/09\/100-negative-eigenvalue-in-buckling-analysis\/","url_meta":{"origin":1558,"position":0},"title":"#100: Negative eigenvalue in buckling analysis","author":"gantovnik","date":"2020-09-25","format":false,"excerpt":"#100: Negative eigenvalue in buckling analysis In buckling analysis, a negative eigenvalue implies that the load that causes the structure to buckle is opposite to the direction of the applied load. A negative eigenvalue means that the critical load has a reversed direction compared to the applied load. Applying a\u2026","rel":"","context":"In &quot;nastran&quot;","block_context":{"text":"nastran","link":"https:\/\/gantovnik.com\/bio-tips\/category\/nastran\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":479,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/03\/what-does-a-negative-eigenvalue-in-a-buckling-analysis-mean\/","url_meta":{"origin":1558,"position":1},"title":"#69 What does a negative eigenvalue in a buckling analysis mean?","author":"gantovnik","date":"2020-03-04","format":false,"excerpt":"A negative eigenvalue in a buckling analysis may imply that the buckling load is in the opposite direction of the applied load. For example, for a simply supported beam, if a tensile axial load is applied to one end, then the eigenvalue will be negative. One the other hand, for\u2026","rel":"","context":"In &quot;nastran&quot;","block_context":{"text":"nastran","link":"https:\/\/gantovnik.com\/bio-tips\/category\/nastran\/"},"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":1558,"position":2},"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 &quot;HyperMesh&quot;","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":1558,"position":3},"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 &quot;HyperMesh&quot;","block_context":{"text":"HyperMesh","link":"https:\/\/gantovnik.com\/bio-tips\/category\/hypermesh\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":648,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/09\/105-how-to-remove-offsets-defined-on-shell-and-beams\/","url_meta":{"origin":1558,"position":4},"title":"#105: How to remove offsets defined on shell and beams?","author":"gantovnik","date":"2020-09-25","format":false,"excerpt":"#105: How to remove offsets defined on shell and beams? Method 1: Properties > Modify > GLOBAL Method 2: Utility > Property > Property Editor Property Words to Change: 4111 Plate Offset, Only Process If Exists: Check, Action: =, Value: 0 Offsets should not be used for the beam and\u2026","rel":"","context":"In &quot;nastran&quot;","block_context":{"text":"nastran","link":"https:\/\/gantovnik.com\/bio-tips\/category\/nastran\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":936,"url":"https:\/\/gantovnik.com\/bio-tips\/2021\/06\/168-nastran-sol-106-vs-sol-400\/","url_meta":{"origin":1558,"position":5},"title":"#168 Nastran SOL 106 vs SOL 400","author":"gantovnik","date":"2021-06-22","format":false,"excerpt":"#168 Nastran SOL 106 vs SOL 400 It is always challenging when it comes to nonlinear analysis, either it is geometric, material, or contact nonlinearity using SOL 106 in Nastran. For Advanced nonlinear analysis, SOL 400 is a new approach to solve the different types of nonlinear analysis. SOL 400\u2026","rel":"","context":"In &quot;buckling&quot;","block_context":{"text":"buckling","link":"https:\/\/gantovnik.com\/bio-tips\/category\/buckling\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/posts\/1558","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=1558"}],"version-history":[{"count":0,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/posts\/1558\/revisions"}],"wp:attachment":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/media?parent=1558"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/categories?post=1558"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/tags?post=1558"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}