Abstract: Systems and methods of computer aided engineering analysis using hybrid approach of finite element method (FEM) and adaptive smoothed particle hydrodynamics (SPH) are described. According to one aspect, a computer-aided engineering analysis is performed to simulate an impact event between structures. A FEM grid model is created to represent the structures using a plurality of solid elements which represents geometry and material properties. Once a contact between two structures resulted into a material or structural failure according to predefined material constitutive equation, solid elements representing the failed portion of the structure are removed. Each failed solid element is then replaced by a plurality of particles to be analyzed using the SPH analysis. The particles replacing the failed element inherit all of the states and properties of the failed element, such as location, mass, velocity, acceleration, etc.

Abstract: Systems and methods for determining material properties of elastomers for the Mullins effect are described. In one aspect of the present invention, material properties of an elastomer membrane specimen are obtained using a system comprising a bi-axial test device, a pump, a fluid reservoir, a linear variable differential transformer, a pressure transducer and a computer. The bi-axial test device comprises a top plate and a bottom plate. The top plate has an elliptical shape hole configured to allow the specimen to be expanded up by pressures of the inflating fluids. The hole is so dimensioned that the specimen can be expanded with a relatively low pressure. The bottom plate is a solid plate configured with a fluid intake at one side and a fluid outlet at the other end. The fluid intake is connected to the fluid reservoir. Fluids stored in the fluid reservoir are pumped into the bi-axial test device by the pump. The fluid outlet is connected to the pressure transducer.

Abstract: A system, method and software product for simulating fracture propagation in brittle materials is disclosed. Using the fracture energy release rates and the critical separations of the three fundamental fracture modes obtained independently from experiments, and a user defined normalized curve representing the traction-separation law, the present invention simulates the fracture propagation in a non-linear dynamic analysis. By using either dimensional or dimensionless effective separation approach, the actual tractions are calculated at each solution cycle based on user's choice. In addition, loading, unloading and reloading conditions are also continuously traced to ensure the proper constitutive equations are used. Three fracture modes are seamlessly mixed and integrated.

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: Systems and methods for determining material properties of elastomers for the Mullins effect are described. In one aspect of the present invention, material properties of an elastomer membrane specimen are obtained using a system comprising a bi-axial test device, a pump, a fluid reservoir, a linear variable differential transformer, a pressure transducer and a computer. The bi-axial test device comprises a top plate and a bottom plate. The top plate has a circular hole configured to allow the specimen to be expanded up by pressures of the inflating fluids. The circular hole is so dimensioned that the specimen can be expanded with a substantially low pressure. The bottom plate is a solid plate configured with a fluid intake at one side and a fluid outlet at the other end. The fluid intake is connected to the fluid reservoir. Fluids stored in the fluid reservoir are pumped into the bi-axial test device by the pump. The fluid outlet is connected to the pressure transducer.

Abstract: A system and method for designing stamping tools that produce parts of desired dimensions. The system and method compensate for post stamping deviations from the desired dimensions in the shape of the tools used to produce the parts. The compensated tools result in nearly ideal parts.

Abstract: A system and method for designing stamping tools that produce parts of desired dimensions. The system and method compensate for post stamping deviations from the desired dimensions in the shape of the tools used to produce the parts. The compensated tools result in nearly ideal parts.

Abstract: Hourglass deformations due to zero-energy or hourglass modes in rank-deficient solid elements must be effectively controlled, or the deformations may grow large and produce an unrealistic deformed geometry. Traditional methods of hourglass control allow error to accumulate by measuring hourglass deformation with incremental terms throughout a solution, which may produce inaccurate results due to unrealistic hourglass deformations. The present invention discloses a new method to control hourglass deformation without any incremental accumulations. Instead the nodal forces to resist hourglass deformations are calculated basing on the initial nodal coordinates and current nodal coordinates at each cycle. The present invention is implemented in a finite element software product.

Abstract: A system, method and software product for modeling spot welds in a finite element analysis is described. The spots welds are represented by beam elements or solid elements in accordance with an indicator flag. The flag may also be specified as the number (e.g., an integer such as 1, 4, 8 or 16) of solid elements in a cluster representing spot weld. The solid elements may include, but not limited to, hexahedron, tetrahedron, and the likes. The number of solid elements and required nodes are generated for each spot weld based on the indicator flag. A table is formed to group the generated solid elements in a cluster together, so that the force and moment resultants of the spot weld can be computed and assembled in a file.

Abstract: A method for performing a finite element simulation. The method includes switching between an implicit method and an explicit method during the finite element simulation. By switching between the implicit and explicit methods during a simulation, an accurate solution can be obtained quickly and reliably.

Abstract: A computer system and method for performing a finite element analysis to determine the final dimensions of an object comprising automatically switching from an Eulerian formulation to a Lagrangian formulation during the analysis.

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.