Abstract:
Due to geometric discontinuities introduced by welding and joining processes, stresses or strain cannot be calculated reliably calculated using modern analytical and computer methods as result of stress or strain singularity at joint locations, which leads to severe mesh sensitivity. Design and fatigue evaluation of these structures remain empirical. This disclosure addresses mesh insensitivity of stress/strain calculations for welded structures through a cut-plane traction stress method through a novel post processing of conventional finite element computation results, as well as provides a unified fatigue evaluation procedure for fatigue design and structural life evaluation for both low-cycle and high cycle fatigue regime subjected to either proportional or non-proportional multiaxial fatigue loading, as well as a simple and reliable method for treating spot welds.
Abstract:
A joint analyzing method includes: performing a data measurement; performing a detailed analysis; performing a simplified analysis; performing a first repetition analysis in which the detailed analysis is repeated while modifying a first analysis model in which geometry of a joint surrounding region is modeled and an analysis technique in the detailed analysis, until a data measurement result and a detailed analysis result are brought into agreement; and performing a second repetition analysis in which the simplified analysis that takes into consideration an initial internal load of at least one junction in a load non-applied state obtained in the first repetition analysis is repeated while modifying a second analysis model rougher in element division of the geometry than the first analysis model and an analysis technique in the simplified analysis, until the data measurement result and a simplified analysis result are brought into agreement.
Abstract:
The present invention discloses an analysis method of a tensioning process of a fine mask plate. The analysis method, based on the simulation function of ANSYS software, finds an appropriate tensile force for stretching a fine mask plate and a corresponding actual counterforce applied to a metal frame before each fine mask plate is welded onto the metal frame through establishing a finite element model of the fine mask plate and a finite element model of the metal frame.. The analysis process requires no physical tests, thereby effectively avoiding damaging the fine mask plate and further effectively saving the test cost.
Abstract:
An elastic response performance prediction method that employs a finite element analysis method to predict an elastic response performance expressing deformation behavior of a rubber product. The elastic response performance of the rubber product is predicted by employing a constitutive equation that expresses temperature and strain dependence of strain energy in the rubber product expressed using a parameter representing intermolecular interaction.
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:
When discretizing an analysis target part into plural elements and performing analysis, sheet thickness reduction rate or maximum principal strain at an equivalent position including a same element is compared by either a manner of combining two adjacent elements after the analysis or a manner of changing an element discretization size with two types and performing the analysis, and the element where the difference is large is extracted as a fracture risk portion.With this structure, a fracture risk portion can be extracted reliably when a fracture is predicted by a finite element method.
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. The replacement is conducted according to the principles of mass, momentum and energy conservation.
Abstract:
According to exemplary embodiments of the present invention, a fracture prediction device for a spot welded portion can be provided. For example, the device may include an input arrangement configured to input all or some of a material strength, a plate thickness, a nugget diameter of a spot welding, a plate width of a joint, and a rotation angle of the joint in a tension test, based on a cross tension test and/or a shear tension test at a spot welded joint. The device can also include a first calculation arrangement configured to calculate a fracture strength parameter of the spot welded portion from all or any of the material strength, the plate thickness, the nugget diameter of the spot welding, the plate width of the joint, and the rotation angle of the joint in the tension test. A parameter storage arrangement may also be provided which can be configured to store the fracture strength parameter by each steel type. Further, the device may further have a second calculation arrangement configured to determine a fracture of the spot welded portion by installing the fracture strength parameter stored in the parameter storage arrangement into a fracture prediction formula in which a deformation at a periphery of the spot welding is modeled by a finite element procedure. Exemplary embodiments of the method software arrangement and computer accessible medium performing similar procedures can also be provided.
Abstract:
Structural stress in a fatigue-prone region of a structure is determined and analyzed by using: i) the nodal forces and displacement values in the fatigue-prone region, or ii) equilibrium equivalent simple stress states consistent with elementary structural mechanics in the fatigue-prone region. Of course, it is contemplated that combinations, equivalents, or variations of the recited bases may alternatively be employed.
Abstract:
A method for crack propagation simulation in which a definition of a three-dimensional structure and of an initial crack are provided, a cut of the structure along a crack propagation is calculated, a new crack front is determined by determining stress values by a finite element calculation and by using a crack propagation function. The propagated crack is then triangulated, and the aforementioned steps are repeated until a predetermined end condition is fulfilled.