{"id":20,"date":"2013-02-26T20:37:53","date_gmt":"2013-02-26T20:37:53","guid":{"rendered":"http:\/\/faculty.engineering.ucdavis.edu\/template\/?page_id=20"},"modified":"2014-10-27T15:55:25","modified_gmt":"2014-10-27T15:55:25","slug":"research","status":"publish","type":"page","link":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/research\/","title":{"rendered":"Research Interests"},"content":{"rendered":"<p>Professor Rashid&#8217;s research activities fall into the broad disciplines of solid mechanics and computational methods. \u00a0Current focus areas include:<\/p>\n<ul>\n<li>Fracture mechanics modeling. \u00a0The Exclusion Region theory\u00a0 of fracture, first published in 1997 by Prof. Rashid, constitutes a general theoretical framework for surface separation &#8211; i.e. fracture &#8211; in solid continua.\u00a0 \u00a0Unlike classical approaches to fracture, the ER theory places no restrictions\u00a0 on the nature of the bulk constitutive behavior, nor on the crack trajectory.\u00a0 \u00a0The ER theory is essentially a broadened constitutive formalism that\u00a0 applies in the near-tip region, and which admits the kinematics of \u00a0surface\u00a0 separation. \u00a0In the ER theory, the fracture behavior itself, as distinct\u00a0 from the bulk material response, is the subject of a separate constitutive\u00a0 specification, in the form of a &#8220;separation function.&#8221; \u00a0Recent activities\u00a0 include calibration of the separation function for a number of ductile metals,\u00a0 and computational studies of \u00a0non-self-similar ductile crack growth near functionally graded interfaces in elastic-plastic materials.<\/li>\n<li>Computational fracture mechanics. \u00a0To support the technological application of the ER theory, a nonlinear, quasistatic, finite-element-based computational capability has been synthesized. \u00a0The code, called FEFRAC, has matured into a robust and flexible analysis tool for elastic-plastic fracture mechanics studies. \u00a0The code contains a number of \u00a0innovative features, including a &#8220;moving mesh patch&#8221; construct which allows for arbitrary (and\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <i>a priori<\/i> unknown) crack paths, and a highly effective iterative\u00a0 scheme which simultaneously enforces both equilibrium and the separation criterion.<\/li>\n<li>The Variable-Element-Topology Finite Element Method (VETFEM). \u00a0The\u00a0 VETFEM is a general-purpose finite element method in which each element is\u00a0 free to take essentially any polygonal (polyhedral in 3D) shape. \u00a0The\u00a0 VETFEM retains all of the powerful features of the conventional FEM, while\u00a0 exhibiting the additional advantage that automatic mesh generation is enormously\u00a0 simplified.<\/li>\n<li>Blast loading \/ fluid-structure interaction. \u00a0Current work\u00a0 involves use of a novel incompatible-embedded-mesh method in which inter-mesh\u00a0 compatibility is enforced in a variationally consistent manner. \u00a0This\u00a0 allows the fluid and solid meshes to be constructed independently of each\u00a0 other, thereby greatly reducing the burden associated with carrying out the\u00a0 analysis.<\/li>\n<li>MEMS devices. \u00a0Of particular interest are nonlinear thermomechanical\u00a0 and electromechanical phenomena, such as buckling and snap-through. \u00a0In\u00a0 collaborative work with Professor Rosemary Smith (Univ. of Maine Electrical\u00a0 Engineering), a bistable device has been analyzed in which buckling is used\u00a0 to provide an irreversible indication of a specified temperature excursion.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Professor Rashid&#8217;s research activities fall into the broad disciplines of solid mechanics and computational methods. \u00a0Current focus areas include: Fracture mechanics modeling. \u00a0The Exclusion Region theory\u00a0 of fracture, first published in 1997 by Prof. Rashid, constitutes a general theoretical framework for surface separation &#8211; i.e. fracture &#8211; in solid continua.\u00a0 \u2026 <a class=\"continue-reading-link\" href=\"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/research\/\"> Continue reading <span class=\"meta-nav\">&rarr; <\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"template-twocolumns-left.php","meta":{"inline_featured_image":false,"ngg_post_thumbnail":0,"footnotes":""},"class_list":["post-20","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/wp-json\/wp\/v2\/pages\/20","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/wp-json\/wp\/v2\/comments?post=20"}],"version-history":[{"count":22,"href":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/wp-json\/wp\/v2\/pages\/20\/revisions"}],"predecessor-version":[{"id":252,"href":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/wp-json\/wp\/v2\/pages\/20\/revisions\/252"}],"wp:attachment":[{"href":"https:\/\/faculty.engineering.ucdavis.edu\/rashid\/wp-json\/wp\/v2\/media?parent=20"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}