A non-transitory computer-readable recording medium storing a distortion calculation program that causes a computer to execute a process includes: analyzing a distortion which occurs in an object when stress is applied, referring to a storage which stores a distortion amplitude for each of nodes of a mesh which is created for the object, moving, onto a circumference which is determined by a set radius, one or more nodes within a width set from the circumference by using a point selected from the nodes of the mesh as a starting point, creating a distribution chart of values of the distortion amplitude of the one or more nodes on the circumference after movement, and displaying the distribution chart on a display device.

The invention relates to a method for estimating (100) stress intensity factors (FIC) in a numerically modelled part, in the context of a fatigue crack propagation model, comprising the following steps: (E2): obtaining, from a numerical model of the part to be analysed (20), a plurality of values simulated at various points of the part to be analysed (20), (E3): determining a converted value (K) of the effective stress intensity amplitude corresponding to a straight front of a planar crack, as well as a converted length (a) of the crack corresponding to a planar crack with a straight front, said converted values being determined by equalisation of the energy dissipated in the three-dimensional crack of the numerical model and the energy dissipated in the crack of a standard model of a planar crack with a straight front, (E4): interpolating converted values of effective stress intensity factor amplitude between two successive converted lengths (a), (E5): storing the converted values of effective stress intensity factor amplitude interpolated in this way.

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.

A method for generating a test coupon specification for predicting fatigue life of a component includes determining a load condition for the component, providing a component design, and performing a strength analysis of the component design under the load condition determining a critical area of the component and a stress-related parameter of the critical area. The method includes providing a material condition of the component at least for the critical area of the component. To assist an end-user in determining which are optimal tests to be performed in order to obtain most relevant data for fatigue prediction of a specific component, the method also includes providing a material model and providing, as an input to the material model, the stress-related parameter, and the material condition. The material model generates, as an output, a test coupon specification for being tested in a testing machine.

[Object] To provide an information processing apparatus capable of predicting crack generation in a structure by ductile fracture in a short time, an information processing method, and a program. [Solving Means] An information processing apparatus includes a model acquisition unit and a crack prediction unit. The model acquisition unit acquires a structure model corresponding to a predetermined structure. The crack prediction unit predicts crack generation in the structure by calculating a differential equation including a term set at each position of the structure model and in proportion to a time differential of a crack variable that expresses presence or absence of a crack and a term set at each position of the structure model and in proportion to plastic dissipation energy that expresses energy dissipated at the time of plastic deformation by utilizing the crack variable. With this configuration, by calculating a differential equation using a crack variable that expresses presence or absence of a crack and plastic dissipation energy that expresses energy dissipated at the time of plastic deformation by utilizing the crack variable, crack generation by ductile fracture is predictable.

A method of determining a maximum acceptable alternating stress at a point of a part subjected to cyclic loading: simulating that the part is subjected to constant loading equal to a threshold value during a level period, and assuming that the part has elasto-viscoplastic behavior; from the results of the simulation, determining a final static stress at the point at the end or after the end of the level period; and for the point under consideration, using a Goodman diagram to determine the maximum acceptable alternating stress, which is determined for a static stress equal to the final static stress; the duration of the level period being equal to the duration of the loading of the testpieces that were used to draw up the Goodman diagram.

An object of the invention is to provide a simple method and apparatus for evaluating a collapse load of a structure with respect to ductile fracture in the case where a plurality of flaws exist in a cylindrical structure that receives a bending load. The invention is an evaluation method and apparatus in which a result obtained by calculating a collapse load while a flaw having the largest area among a plurality of flaws is considered as a single flaw and a result obtained by replacing a plurality of flaws with penetration flaws corresponding to the plurality of flaws and calculating a collapse load are compared with each other and the smallest collapse load is set to be a collapse load of a structure.

A bending fracture limit stress is calculated for each of (bend radius at sheet thickness center of a metal sheet)/(initial sheet thickness of the metal sheet); a fracture limit curve and a fracture limit stress are calculated from work hardening characteristics; a fracture limit curve corresponding to (the metal sheet bend radius at sheet thickness center)/(the initial sheet thickness of the metal sheet) is calculated; a corresponding fracture limit stress is calculated from stress of the element subject to determination and the fracture limit curve; a risk ratio that is a ratio between the stress of the element subject to determination and the fracture limit stress is computed; and performing fracture determination for the element subject to determination based on the risk ratio.

Sheet metal is provided as a template to create a finished product. After various metal transformation techniques are performed on the sheet metal, the sheet metal may be converted to the finished product. The sheet metal manipulation may encompass different techniques, such as thinning, bending, cutting, and the like. The manipulated sheet metal may be sourced for various products, such as a body of a vehicle.

A method for generating a test coupon specification for predicting fatigue life of a component includes determining a load condition for the component, providing a component design, and performing a strength analysis of the component design under the load condition determining a critical area of the component and a stress-related parameter of the critical area. The method includes providing a material condition of the component at least for the critical area of the component. To assist an end-user in determining which are optimal tests to be performed in order to obtain most relevant data for fatigue prediction of a specific component, the method also includes providing a material model and providing, as an input to the material model, the stress-related parameter, and the material condition. The material model generates, as an output, a test coupon specification for being tested in a testing machine.