Matches in SemOpenAlex for { <https://semopenalex.org/work/W2336148935> ?p ?o ?g. }
Showing items 1 to 86 of
86
with 100 items per page.
- W2336148935 abstract "The recently developed isogeometric analysis (IGA) was aimed, from the start, at integrating computer aided design (CAD) and analysis. This synthesis of geometry and analysis has naturally led to renewed interest in developing structural shape optimization. The advantages of using isogeometric analysis in shape optimization are embodied in its ability to preserve exact CAD geometrical descriptions and its enhanced potential to perform shape sensitivity analysis. Recent contributions in shape optimization within IGA have been limited to static or steady-state loading conditions. The purpose of this work was to extend the isogeometric shape optimization and identification to quasi-static and transient problems. The normalization approaches for the search directions in isogeometric shape optimization scheme and the mean value property of B-spline basis were also studied. Shape sensitivity analysis plays a critical role in structural shape optimization. In this dissertation, an adjoint sensitivity analysis was performed for arbitrary objective functionals defined for quasi-static and transient problems at the continuous level. The sensitivity for quasi-static and transient problems are essentially different with each other since the transient case has a time-derivative term involved in the time interval. The transport relations considering discontinuities were studied and used to derive the continuous adjoint shape sensitivity. Consideration of the discontinuities enabled the shape sensitivity analysis to be applicable for the problems where discontinuities were involved in the objective functional and state equations. Then within the context of IGA, the continuous sensitivity was discretized to obtain the discrete design sensitivity with respect to the design discretization, which was used to find the search directions used to update the shape numerically. A interesting phenomenon in shape optimization is that the use of the search direction directly predicted from the discrete shape gradient makes the optimization history strongly dependent on the discretization. This discretization dependency can affect convergence and may lead the optimization process into a sub-optimal solution. The source of this discretization dependency was traced to the lack of consistency with the local steepest descent search direction in the continuous formulation. This inconsistency was analyzed using the shape variation equations and subsequently illustrated with a volume minimization problem. It was found that the inconsistency originates from the NURBS discretization which induces a discrete quadratic norm to represent the continuous Euclidean norm. To fix this inconsistency, a standard normalization approach, which is used to find the steepest descent direction for quadratic norm problems, was proposed to obtain a consistent discretization independent search direction. The standard approach requires solving a linear system of equations. Using the diagonally lumped mapping matrix (DLMM) and the partition of unity property of NURBS, two simpler normalization approaches, which do not require solving a linear system of equations, were proposed. The discretization-independence of the proposed approaches was verified with a benchmark problem. The superiority of the proposed search direction and its suitability for numerical implementation is illustrated with examples of shape optimization for mechanical and thermal problems. In the derivation of the simplified normalization approaches, the mean value property of B-spline basis function is proposed and proved using mathematical induction method. Using the normalization approaches, two frameworks to solve shape optimization and identification problems for quasi-static and transient process, respectively, were developed and implemented numerically within the context of isogeometric analysis. Generalized objective functionals were used to accommodate both structural shape optimization and identification problems in arbitrary forms. The methodology and its numerical implementation were tested using benchmark problems or passive control approaches with priori known solutions. For the quasi-static case, application problems were considered where an external load was allowed to move along the surface of a structure. The shape of the structure was modified to control the time-dependent displacement of the point where the load was applied according to a pre-specified target. For the transient case, the shape optimization and identification was performed for a plunger design under a transient heating process and a thermal protection layer design for a ballistic re-entry vehicle." @default.
- W2336148935 created "2016-06-24" @default.
- W2336148935 creator A5085074236 @default.
- W2336148935 date "2016-01-20" @default.
- W2336148935 modified "2023-09-25" @default.
- W2336148935 title "Isogeometric Shape Optimization for Quasi-static and Transient Problems" @default.
- W2336148935 doi "https://doi.org/10.4233/uuid:a05a8c81-5f02-4d12-9417-8fdba05e6983" @default.
- W2336148935 hasPublicationYear "2016" @default.
- W2336148935 type Work @default.
- W2336148935 sameAs 2336148935 @default.
- W2336148935 citedByCount "0" @default.
- W2336148935 crossrefType "journal-article" @default.
- W2336148935 hasAuthorship W2336148935A5085074236 @default.
- W2336148935 hasConcept C111915175 @default.
- W2336148935 hasConcept C111919701 @default.
- W2336148935 hasConcept C112604564 @default.
- W2336148935 hasConcept C126255220 @default.
- W2336148935 hasConcept C127413603 @default.
- W2336148935 hasConcept C134306372 @default.
- W2336148935 hasConcept C135628077 @default.
- W2336148935 hasConcept C136886441 @default.
- W2336148935 hasConcept C144024400 @default.
- W2336148935 hasConcept C15627037 @default.
- W2336148935 hasConcept C19165224 @default.
- W2336148935 hasConcept C199360897 @default.
- W2336148935 hasConcept C21200559 @default.
- W2336148935 hasConcept C24326235 @default.
- W2336148935 hasConcept C2780737243 @default.
- W2336148935 hasConcept C2780799671 @default.
- W2336148935 hasConcept C28826006 @default.
- W2336148935 hasConcept C29513896 @default.
- W2336148935 hasConcept C33923547 @default.
- W2336148935 hasConcept C41008148 @default.
- W2336148935 hasConcept C66938386 @default.
- W2336148935 hasConcept C73000952 @default.
- W2336148935 hasConcept C97686452 @default.
- W2336148935 hasConceptScore W2336148935C111915175 @default.
- W2336148935 hasConceptScore W2336148935C111919701 @default.
- W2336148935 hasConceptScore W2336148935C112604564 @default.
- W2336148935 hasConceptScore W2336148935C126255220 @default.
- W2336148935 hasConceptScore W2336148935C127413603 @default.
- W2336148935 hasConceptScore W2336148935C134306372 @default.
- W2336148935 hasConceptScore W2336148935C135628077 @default.
- W2336148935 hasConceptScore W2336148935C136886441 @default.
- W2336148935 hasConceptScore W2336148935C144024400 @default.
- W2336148935 hasConceptScore W2336148935C15627037 @default.
- W2336148935 hasConceptScore W2336148935C19165224 @default.
- W2336148935 hasConceptScore W2336148935C199360897 @default.
- W2336148935 hasConceptScore W2336148935C21200559 @default.
- W2336148935 hasConceptScore W2336148935C24326235 @default.
- W2336148935 hasConceptScore W2336148935C2780737243 @default.
- W2336148935 hasConceptScore W2336148935C2780799671 @default.
- W2336148935 hasConceptScore W2336148935C28826006 @default.
- W2336148935 hasConceptScore W2336148935C29513896 @default.
- W2336148935 hasConceptScore W2336148935C33923547 @default.
- W2336148935 hasConceptScore W2336148935C41008148 @default.
- W2336148935 hasConceptScore W2336148935C66938386 @default.
- W2336148935 hasConceptScore W2336148935C73000952 @default.
- W2336148935 hasConceptScore W2336148935C97686452 @default.
- W2336148935 hasLocation W23361489351 @default.
- W2336148935 hasOpenAccess W2336148935 @default.
- W2336148935 hasPrimaryLocation W23361489351 @default.
- W2336148935 hasRelatedWork W139263151 @default.
- W2336148935 hasRelatedWork W1509166644 @default.
- W2336148935 hasRelatedWork W1610215877 @default.
- W2336148935 hasRelatedWork W2015636866 @default.
- W2336148935 hasRelatedWork W2086584437 @default.
- W2336148935 hasRelatedWork W2104076473 @default.
- W2336148935 hasRelatedWork W2113337913 @default.
- W2336148935 hasRelatedWork W2317427410 @default.
- W2336148935 hasRelatedWork W2410304179 @default.
- W2336148935 hasRelatedWork W2600515226 @default.
- W2336148935 hasRelatedWork W2626793241 @default.
- W2336148935 hasRelatedWork W2782356153 @default.
- W2336148935 hasRelatedWork W3003728131 @default.
- W2336148935 hasRelatedWork W3023529123 @default.
- W2336148935 hasRelatedWork W3023863322 @default.
- W2336148935 hasRelatedWork W3034175654 @default.
- W2336148935 hasRelatedWork W3131608052 @default.
- W2336148935 hasRelatedWork W3190255739 @default.
- W2336148935 hasRelatedWork W34622074 @default.
- W2336148935 hasRelatedWork W2912264158 @default.
- W2336148935 isParatext "false" @default.
- W2336148935 isRetracted "false" @default.
- W2336148935 magId "2336148935" @default.
- W2336148935 workType "article" @default.