Abstract: A global computer aided engineering (CAE) model representing an electronic product that contains solder joints and an individual detailed solder joint model are received. The solder joint model can include a solder ball, one or more metal pads, a portion of printed circuit board, and a portion of semiconductor chip component. The global CAE model includes locations of the solder joints to be evaluated in a drop test simulation. The solder joint model is replicated at each location to create a local CAE model via a geometric relationship between the global CAE model and the local CAE model. Simulated physical behaviors of the product under a design condition are obtained in a co-simulation using the global CAE model in a first time scale and the local CAE model in a second time scale. Simulated physical behaviors are periodically synchronized based on kinematic and force constraints.

Abstract: Meshfree model containing a number of particles to represent a structure made of brittle material is defined. At each non-initial solution cycle of a numerical simulation using the meshfree model based on damage mechanics, the following operations are performed: (a) determining one or more damage zones in the structure from simulated structural responses obtained in immediate prior solution cycle; (b) dividing the particles into a first group representing the damage zones and a second group representing the remaining of the meshfree model; (c) applying a meshfree regularization scheme by modifying each particle's strain field of the first group with a morphing function that ensures a homogeneous jump condition along respective borders of the damage zones; and (e) obtaining simulated structural behaviors of the structure using a meshfree stabilization scheme that applies to all of the particle's strain field. Each damage zone represents a crack that can grow over time.

Abstract: Meshfree model containing a number of particles to represent a structure made of brittle material is defined. At each non-initial solution cycle of a numerical simulation using the meshfree model based on damage mechanics, the following operations are performed: (a) determining one or more damage zones in the structure from simulated structural responses obtained in immediate prior solution cycle; (b) dividing the particles into a first group representing the damage zones and a second group representing the remaining of the meshfree model; (c) applying a meshfree regularization scheme by modifying each particle's strain field of the first group with a morphing function that ensures a homogeneous jump condition along respective borders of the damage zones; and (e) obtaining simulated structural behaviors of the structure using a meshfree stabilization scheme that applies to all of the particle's strain field. Each damage zone represents a crack that can grow over time.

Abstract: Methods and systems for conducting numerical simulation of structural behaviors in solid mechanics using smoothed particle Galerkin formulation are disclosed. A meshfree model representing a physical domain defined by a plurality of particles is received in a computer system. Each particle is configured for material properties of portion of the physical domain it represents. A smoothed displacement field of the physical domain subject to defined boundary condition is obtained by conducting a time-marching simulation using the meshfree model based on smoothed particle Galerkin formulation. The smoothed displacement field is derived from a set of smoothed meshfree shape functions that satisfies linear polynomial reproduction condition. The set of smoothed meshfree shape functions is constructed by convex meshfree approximation scheme and configured to avoid calculation second order derivatives.

Abstract: Methods and systems for numerically simulating structural behaviors of embedded bi-materials are disclosed. At least first and second grid models are created independently for an embedded bi-material that contains an immersed material embedded entirely within a base material. First group of meshfree nodes represents the entire domain (i.e., base plus immersed materials). Second group of meshfree nodes represents the immersed or embedded material, which includes all interface nodes and nodes located within a space bordered by the material interface. Numerical structural behaviors of the embedded bi-material are simulated using the first and second set of meshfree nodes with a meshfree method that combines two meshfree approximations. The first meshfree approximation covers the first set of meshfree nodes and is based on properties of the base material, while the second meshfree approximation covers the second set of meshfree nodes and is based on a differential between the immersed and base materials.

Abstract: System, method and software product for numerically simulating structural behaviors of an engineering product in compressible and near-incomprssible region is disclosed. Meshfree enriched finite element method (ME-FEM) is used for such numerical simulation. ME-FEM requires an engineering product be represented by a FEM model comprising a plurality of finite elements. Finite elements used in the ME-FEM are generally low-order finite elements. Each of the finite elements in the FEM model is enriched by at least one meshfree enriched (ME) node located within the element's domain. Each ME node has additional degrees-of-freedom for the element it belongs independent from those of the corner nodes. A displacement based first-order convex meshfree approximation is applied to the ME node. The convex meshfree approximation has Knonecker-delta property at the element's boundary. The gradient matrix of ME-FEM element satisfies integration constraint.

Abstract: Methods and systems for numerically simulating structural behaviors of embedded bi-materials are disclosed. At least first and second grid models are created independently for an embedded bi-material that contains an immersed material embedded entirely within a base material. First group of meshfree nodes represents the entire domain (i.e., base plus immersed materials). Second group of meshfree nodes represents the immersed or embedded material, which includes all interface nodes and nodes located within a space bordered by the material interface. Numerical structural behaviors of the embedded bi-material are simulated using the first and second set of meshfree nodes with a meshfree method that combines two meshfree approximations. The first meshfree approximation covers the first set of meshfree nodes and is based on properties of the base material, while the second meshfree approximation covers the second set of meshfree nodes and is based on a differential between the immersed and base materials.

Abstract: System, method and software product for numerically simulating structural behaviors of an engineering product in compressible and near-incomprssible region is disclosed. Meshfree enriched finite element method (ME-FEM) is used for such numerical simulation. ME-FEM requires an engineering product be represented by a FEM model comprising a plurality of finite elements. Finite elements used in the ME-FEM are generally low-order finite elements. Each of the finite elements in the FEM model is enriched by at least one meshfree enriched (ME) node located within the element's domain. Each ME node has additional degrees-of-freedom for the element it belongs independent from those of the corner nodes. A displacement based first-order convex meshfree approximation is applied to the ME node. The convex meshfree approximation has Knonecker-delta property at the element's boundary. The gradient matrix of ME-FEM element satisfies integration constraint.

Abstract: A method, system and computer program product pertained to adaptive discretization refinement of shell structure is disclosed. The adaptive mesh-free model is based on a technique for dividing the critical area into a finer model. The present invention is a method for enabling adaptive mesh-free shell structure in a time-domain analysis, the method comprises: defining the mesh-free shell structure by a structural geometry description file including a plurality of nodes and a reference 3-D mesh, which includes a plurality of shell elements, mapping the 3-D reference mesh into a 2-D parametric plane, wherein the 2-D parametric mesh includes a plurality of integration cells corresponding to the plurality of shell elements, solving structural responses at current solution cycle using mesh-free mathematical approximations pertaining to each of the plurality of integration cells, performing adaptive discretization refinement for the plurality of the integration cells.

Abstract: A two-level transformation scheme to enable a practical fast mesh-free method is disclosed. The first level transformation transforms the original chosen mesh-free shape function to a first transformed mesh-free shape function that preserves Kronecker delta properties. The first transformed mesh-free function allows the essential boundary conditions to be imposed directly. The second-level transformation scheme employs a low pass filter function served as a regularization process that filters out the higher-order terms in the monomial mesh-free approximation obtained from the first-level transformation scheme with desired consistency and completeness conditions. This integration scheme requires only a low-order integration rule comparing to the high order integration rule used in the traditional mesh-free methods. The present invention simplifies the boundary condition treatments and avoids the usage of high-order integration rule and therefore is more practical than the traditional mesh-free methods.

Abstract: A method, system and computer program product pertained to engineering analysis of a general three-dimensional (3-D) shell structure using the mesh-free technique is disclosed. The structural responses are solved with mesh-free technique after the 3-D shell structure is mapped to a two-dimensional plane. According to one aspect, the present invention is a method for mesh-free analysis of a general three-dimensional shell structure, the method comprises: defining the general shell structure as a physical domain represented by a plurality of nodes in a three-dimensional space, creating a plurality of projected nodes by mapping the plurality of nodes in the three-dimensional space onto a two-dimensional plane, assigning a plurality of domain of influences, one for each of the plurality of projected nodes, and calculating a solution of the physical domain using a set of mathematical approximations pertaining to each of the plurality of projected nodes.

Abstract: A method and system for transferring state variables between an old and new model in an adaptive mesh-free analysis is described. The old and the new model are associated with a set of old and new integration points, respectively. A third set of nodes is formed to include old boundary nodes and the set of old integration points. For each of the new integration points, a sub-set of the third set is defined. The support of each node of the sub-set covers the new integration point to be evaluated. A local interpolant with a desirable consistency condition and interpolation properties is constructed to interpolate state variables at the new integration points. All of the non-interpolated approximation can be transformed into the interpolated approximation with the desired consistency condition and smoothness using this procedure.

Abstract: A method, system and computer program product pertained to engineering analysis of a general three-dimensional (3-D) shell structure using the mesh-free technique is disclosed. The structural responses are solved with mesh-free technique after the 3-D shell structure is mapped to a two-dimensional plane. According to one aspect, the present invention is a method for mesh-free analysis of a general three-dimensional shell structure, the method comprises: defining the general shell structure as a physical domain represented by a plurality of nodes in a three-dimensional space, creating a plurality of projected nodes by mapping the plurality of nodes in the three-dimensional space onto a two-dimensional plane, assigning a plurality of domain of influences, one for each of the plurality of projected nodes, and calculating a solution of the physical domain using a set of mathematical approximations pertaining to each of the plurality of projected nodes.