Abstract: Systems and methods of providing bonded-particle model amongst a plurality of discrete particles representing a physical domain made of brittle material in a time-marching simulation to obtain numerically simulated continuum physical phenomena are disclosed. A physical domain is represented by a plurality of discrete particles. A domain of influence is assigned to each discrete particle and a bonded-particle model is created for the discrete particles. Respective bonds are established to connect each discrete particle to all other discrete particles within its domain of influence. The bonded-particle model further defines a rule for breakage of a bond. Continuum physical phenomena of the physical domain are numerically represented through a set of formula such that a time-marching simulation of the physical domain can be conducted. Physical properties include material properties and fracture energy release rate. Finally, the bonded-particle model allows size and orientation changes of each discrete particle.

Abstract: Systems and methods of selecting sampling points (product designs) in a multi-objective engineering design optimization of a product are disclosed. The method comprises (a) receiving a description of the product to be optimized, (b) selecting an initial set of sampling points in a design variable space of the product, (c) obtaining numerically-simulated structural responses of each of the current set, (d) deriving a set of approximate POPs from optimization using metamodels constructed from numerically-simulated structural responses, (e) establishing subregions around POF kernels that are selected from approximate POPs using “Piercing” procedure, (f) creating a set of Diversity Basis Points by populating the subregions with a space filling criterion, (g) selecting another set of sampling points from a combined group of the Diversity Basis Points and POF kernels using “Piercing” procedure, (h) reducing the subregion size, and (i) repeating (c)-(h) until a termination condition has been reached.

Abstract: Methods and systems for numerically simulating structural behaviors of a product using explicit FEA with a combined technique of subcycling and mass scaling are disclosed. A FEA model representing a product and a minimum time step size (?tmin) for a time-marching simulation of the product are specified. N element groups is established with the first element group associated with ?tmin as required minimum time step size, while other element groups with integer multiples of ?tmin according to formula ?ti=2i-1?tmin, n=1, 2, . . . , N. Finite elements are periodically resorted into N element groups based on their new respective ?tcr. To ensure all finite elements in the FEA model are processed at the user specified minimum time step size, proper amount of mass scaling is applied to those finite elements that are or have become too small to maintain a stable solution in the first element group.

Abstract: Methods and systems for numerically simulating structural behaviors of a product using explicit FEA with a mass scaling enhanced subcycling technique are disclosed. A FEA model of the product defined by a plurality of nodes and finite elements is received. A critical time step size is calculated for each finite element and then assigned to associated nodes. Elements are partitioned into N element groups with first group requiring minimum time step size ?t1 and other element groups requiring respective time step sizes (?tN=2N?1?t1). In order not to resort or repartition the finite elements and still obtain a stable solution, respective proper amounts of mass scaling are applied to those elements that have become too small to maintain a stable solution in their respective element groups. A time-marching simulation using explicit FEA with the mass scaling enhanced subcycling technique is then conducted with such a FEA model.

Abstract: A computer-implemented method of simulating an impact event in a finite element analysis used for assisting users to design or improve one or more structures is described. The structures are represented in a finite element analysis model that is divided or partitioned into a plurality of domains. Efficiency of the method is achieved when used in a computer system having multiple processing units and multiple contact interfaces defined and specified by users (engineers and/or scientists). Each domain is associated with or assigned to one of the processing units. A “group-able” correlation is established or determined between domains and contact interfaces so that data communications can be conducted in most efficient manner, for example, minimizing idle processing units during data communications.

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: Systems and methods for refining ALE elements in a time-marching simulation are disclosed. A FEA model representing a physical domain is defined and used in a time-marching simulation that simulates physical phenomena of the physical domain. Certain ones of the ALE elements are refined upon detecting a user-defined triggering condition. Each of said certain ones of the ALE elements is refined into a number of child elements. When an ALE element contains more than one material, volume fractions representing respective materials are calculated in each of the child elements right after each refinement. At each advection phase, each donor maps its flux to one or more receptors. When a donor maps its flux to multiple receptors, each receptor calculates its own share of the flux from the donor. When the donor contains more than one material, each receptor must account for such situation.

Abstract: Systems and methods for numerically simulating muscle's movements along bones and around joints are disclosed. A computerized model containing a plurality of truss elements along with one or more rollers is used. The truss elements are configured for modeling a muscle strand while each roller is configured for a joint. Each truss element includes two end nodes and is configured or associated with a muscle bio-mechanical property model. Each roller is fixed at the location of a corresponding joint. To simulate the muscle strand movements around the joint, each pair of truss elements straddling a roller is adjusted dynamically in a time-marching simulation (e.g., computer simulation of an impact event of an automobile and one or more occupants). Adjustments are performed at each solution cycle of the time-marching simulation. Adjustments include two types—“slipping” and “swapping”.

Abstract: Efficient method of rendering a computerized model to be displayed on a computer monitor is disclosed. The computerized model contains a plurality of finite elements organized in groups with each group containing same type of finite elements. For achieving efficient rendering of the computerized model, first and second threshold numbers for further partitioning the computerized model are determined using a set of criteria based on available resources of the computer system and characteristics of the computerized model. Any group having the number of elements more than the first number is divided into subgroups. The number of elements in each subgroups is configured to contain no more than the second number. Both first and second numbers are “tune-able” for particular situations depending upon a number of factors including, but not limited to, power of computer processor, random access memory available, power of graphical co-processor and/or associated memory, and communication bandwidth.

Abstract: Systems and methods of determining structural failure in a computer simulation of manufacturing a sheet metal part are disclosed. A FEA model defined for a sheet metal manufacturing procedure includes a plurality of shell elements representing sheet metal blank. Shell elements are configured for emulating anisotropic material properties of the sheet metal. Numerically-simulated structural behaviors are obtained by conducting a computer simulation of manufacturing the sheet metal part using the FEA model with a metal forming simulation application module. The numerically-simulated structural behaviors include structural deformations in forms of equivalent strain and plastic flow direction during forming of the sheet metal part. A structural failure determination criterion is constructed using a planar isotropic material model of the sheet metal.

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 conducting numerical simulation of a structure having HAZ using a FEA model are disclosed. A FEA model includes at least a group of finite elements representing a welded structural part that encompasses at least one HAZ is defined and received in a computer system. Each finite element in the group is configured with at least one integration point according to FEA. The group of finite elements is associated with a set of HAZ material properties representing structural behavior of the welded structural part inside and outside the HAZ. Corresponding material properties are then determined and assigned to each integration point by interpolating the associated set using the shortest heat-propagation distance between each integration point and the heat source locations (e.g., spotwelds' centroid) with an automated procedure that requires no additional input after the HAZ material properties have been defined.

Abstract: Methods and systems of determining a trim line in deep draw manufacturing of a sheet metal part are disclosed. A computerized model of a sheet metal part and the addendum surface geometry are defined. At least one flange portion in the computerized model is identified. Perform a numerical simulation of unfolding of the flange towards the addendum surface by applying a first set of numerical loads to each pair of adjacent finite elements. The first set of numerical loads is configured for flattening out the pair of finite elements with a bending moment determined using relative orientations of the pair finite elements and material properties of the part. A second set of numerical loads is applied to close any remaining gap between the unfolded flange and the addendum thereafter. The outer edge of the flange portions in their final unfolded configuration is designated as a trim line.

Abstract: Systems and methods of creating a computerized model for a deep draw manufacturing simulation of a sheet metal part are disclosed. A series of computer generated visual diagrams are sequentially displayed upon receipt of a request from the user. The request is for creating a computerized model for a specific type of deep draw manufacturing simulation. The computerized model includes certain number of components for each particular type of simulations. The diagrams are configured for attracting the user's attention as to which component is being processed. Each diagram includes icons displayed in three different indicative schemes. The first indicative scheme shows components that have not been processed. The second indicative scheme shows a currently-processed component, while the third indicative scheme shows previously-processed components. The order of the series of diagrams is predetermined for each particular type of simulation hence minimizing human error in creation of the computerized model.

Abstract: Systems and methods for numerically simulating inflation of an airbag configured with more than one connected flexible-boundary volumes (i.e., primary and secondary pouches) are disclosed. A finite element analysis model of such airbag is defined in the airbag's folded configuration. Numerical simulation of inflating the primary pouch is based on corpuscular particle theory by interacting simulated corpuscular or gas particles with one another and with the shell elements representing the primary pouch. The simulated corpuscular particles are created by flow characteristics generated by an explosive blast. Numerical simulation of inflating the secondary pouch is based on control volume theory by converting kinetic energy of those of the simulated corpuscular particles having flowed through the interconnected opening from the primary to the secondary pouch to a uniform pressure. The uniform pressure is then applied onto the shell elements representing the secondary pouch.

Abstract: Systems and methods of providing bonded-particle model amongst a plurality of discrete particles representing a physical domain made of brittle material in a time-marching simulation to obtain numerically simulated continuum physical phenomena are disclosed. A physical domain is represented by a plurality of discrete particles. A domain of influence is assigned to each discrete particle and a bonded-particle model is created for the discrete particles. Respective bonds are established to connect each discrete particle to all other discrete particles within its domain of influence. The bonded-particle model further defines a rule for breakage of a bond. Continuum physical phenomena of the physical domain are numerically represented through a set of formula such that a time-marching simulation of the physical domain can be conducted. Physical properties include material properties and fracture energy release rate. Finally, the bonded-particle model allows size and orientation changes of each discrete particle.

Abstract: Systems and methods for creating a computerized model containing polydisperse spherical particles packed in an arbitrarily-shaped volume are disclosed. To create the computerized model, a plurality of polydisperse spherical particles having statistical properties according the characteristic profile (e.g., minimum and maximum sizes and size distribution) is generated. First portion of the particles is used for forming a border layer within the volume's boundary. Any hole in the border layer is sealed with one or more null-sized particles. Second portion of the particles is used for filling up an interior space in a layer-to-layer scheme from the border layer inwards. The layer-to-layer scheme includes searching a best suitable location from a list of size-ranked candidate locations using power diagrams. Each of the second portion of the particles is allowed to pass through holes in the current layer towards the border layer when possible.

Abstract: Methods and systems for matching a computed curve to a target curve to enable realistic engineering simulations are disclosed. Discrepancies between computed curve and the target curve are measured, and based on the discrepancies, decisions on how to adjust parametric inputs can be made to achieve an optimal result of simulation. Optimization of parameter identification is achieved by adjusting the parametric inputs of a simulation model such that the discrepancy between the two curves is minimized. Because the points on the two curves to be matched are paired, matching of any two open curves, including hysteretic curves, can be handled. Curves that are complete set apart in their original coordinates can be merged to a common coordinate system for parameter identification without the computational instability problems.

Abstract: Methods and systems for matching a computed curve to a target curve to enable realistic engineering simulations are disclosed. Optimization of parameter identification is achieved by adjusting the parametric inputs of a simulation model such that the discrepancy between the two curves is minimized. Because the points on the two curves to be matched are paired, matching of any two open curves, including hysteretic curves, can be handled. Curves that are completely set apart in their original coordinates can be merged to a common coordinate system for parameter identification without the computational instability problems. A partial matching scheme is used for mapping points defining the shorter one of the two curves to a set of mapped points on the longer one. One or more offsets from the first point of the longer curve are used for multiple attempts to find a best fit.

Abstract: Systems and methods for refining ALE elements in a time-marching simulation are disclosed. A FEA model representing a physical domain is defined and used in a time-marching simulation that simulates physical phenomena of the physical domain. Certain ones of the ALE elements are refined upon detecting a user-defined triggering condition. Each of said certain ones of the ALE elements is refined into a number of child elements. When an ALE element contains more than one material, volume fractions representing respective materials are calculated in each of the child elements right after each refinement. At each advection phase, each donor maps its flux to one or more receptors. When a donor maps its flux to multiple receptors, each receptor calculates its own share of the flux from the donor. When the donor contains more than one material, each receptor must account for such situation.