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EP-3754534-B1 - A FAST METHOD FOR COMPUTER-BASED SIMULATION

EP3754534B1EP 3754534 B1EP3754534 B1EP 3754534B1EP-3754534-B1

Inventors

  • VAN DER VELDEN, ALEXANDER JACOBUS MARIA

Dates

Publication Date
20260513
Application Date
20200614

Claims (12)

  1. A computer-implemented method for performing a computer-based simulation of a car crash, for designing a car to be manufactured, the method comprising: obtaining a mesh-based model representing the car, the mesh-based model being composed of a plurality of mesh elements, wherein (i) the mesh-based model has a mesh size value that is comprised between 15mm and 40mm, (ii) each mesh element represents an area equal to the mesh size value squared, (iii) each mesh element has a geometric property that is element size, and (iv) each mesh element has a material property that is plastic yield strength of steel; and performing a simulation of plastic compression and metal folding during a crash using the mesh-based model, performing the simulation including, for at least one mesh element of the plurality, modifying, as a function of the element size, the plastic yield strength of steel, the modifying of the plastic yield strength of steel as a function of the element size including modifying a stress-strain curve.
  2. The method of Claim 1 further comprising: automatically identifying a design change of the car based on results of the performed simulation.
  3. The method of Claim 2 further comprising: automatically modifying the mesh-based model of the car to correspond to the identified design change.
  4. The method of Claim 3 wherein the performing the simulation, identifying the design change, and modifying the mesh-based model are iterated automatically by a processor until an optimized design of the car is determined.
  5. The method of Claim 1 wherein the mesh-based model is: a finite element model, a finite volume model, or a finite difference method model.
  6. The method of Claim 1 wherein the simulation is a finite element simulation.
  7. The method of Claim 1 wherein, in performing the simulation, the stress-strain curve is modified for periods of time in which the car is undergoing the plastic compression behavior and the stress-strain curve is not modified for periods of time in which the car is not undergoing the plastic compression behavior.
  8. The method of Claim 7 wherein, in performing the simulation, the modified stress-strain curve is applied to shell elements of the mesh-based model.
  9. The method of Claim 1 further comprising: performing a plurality of simulations using a plurality of mesh-based models having varying element sizes; and identifying plastic yield strength of steel modifications using a machine learning analysis of results from the plurality of simulations.
  10. The method of Claim 1 wherein modifying the plastic yield strength of steel as a function of the element size includes modifying a value dictating material behavior given the element size.
  11. A system for performing a computer-based simulation, the system comprising: a processor; and a memory with computer code instructions stored thereon, the processor and the memory, with the computer code instructions, being configured to cause the system to perform the method according to any one of claims 1 to 10.
  12. A computer program product for performing a computer-based simulation, the computer program product executed by a server in communication across a network with one or more clients and comprising program instructions, which when executed, cause the server to perform the method according to any one of claims 1 to 10.

Description

BACKGROUND A number of existing product and simulation systems are offered on the market for the design and simulation of parts, e.g., real-world objects, or assemblies of parts. Such systems typically employ computer aided design (CAD) and computer aided engineering (CAE) programs. These systems allow a user to construct, manipulate, and simulate complex three-dimensional models of objects or assemblies of objects. These CAD and CAE systems provide a model representation of objects ("modeled objects" herein) using edges or lines, in certain cases with faces. Lines, edges, faces, or polygons may be represented in various manners, e.g. non-uniform rational basis-splines (NURBS). These CAD systems manage parts or assemblies of parts of modeled objects, which are mainly specifications of geometry. In particular, CAD files contain specifications, from which geometry is generated. From geometry, a three-dimensional CAD model or model representation is generated. Specifications, geometries, and CAD models/representations may be stored in a single CAD file or multiple CAD files. CAD systems include graphic tools for visually representing the modeled objects as represented in 3-dimensional space to designers; these tools are dedicated to the display of complex real-world objects. For example, an assembly may contain thousands of parts. A CAD system can be used to manage three-dimensional models of real-world objects, which are stored in electronic files. The advent of CAD and CAE systems allows for a wide range of representation possibilities, such as mesh-based models, for objects. CAD models are typically approximated by mesh-based models to enable discrete numerical computation. Thus, mesh-based models may approximate, e.g., represent, one or more parts or an entire assembly. An example mesh-based model is a finite element mesh, which is a system of points called nodes that are interconnected to make a grid, referred to as a mesh. Mesh-based models may be programmed in such a way that the mesh-based model has the properties (e.g., physical, material, or other physics-based) of the underlying real-world object or objects that the mesh-based model represents. Example properties include stiffness (ratio of force to displacement), plasticity (irreversible strain), and viscosity (resistance to flow of one layer over an adjacent layer), amongst others. When a finite element mesh or other such mesh-based model as is known in the art, is programmed in such a way, it may be used to perform simulations of the real-world object that the model represents. For example, a mesh-based model may be used to represent the interior cavity of a vehicle, the acoustic fluid surrounding a structure, or any number of real-world objects. Moreover, CAD and CAE systems, along with mesh-based models, can be utilized to simulate engineering systems, such as real-world physical systems, e.g., cars, planes, buildings, and bridges, amongst other examples. Further, CAE systems can be employed to simulate any variety and combination of behaviors of these physics based systems, such as noise and vibration. SUMMARY Embodiments of the invention generally relate to the field of computer programs and systems and specifically to the field of product design and simulation. As described above, computer-aided systems exist for simulating real-world physical objects, and more particularly simulating physics-based characteristics of the objects. However, these existing systems can benefit from processes that improve speed and efficiency. Improving the speed and efficiency of simulation functionality improves real-world object design and, likewise, improves real-world objects that are manufactured based upon these improved designs. A simulation with improved speed and efficiency is disclosed in COSTAS MIGUEL ET AL: "A through-thickness damage regularisation scheme for shell elements subjected to severe bending and membrane deformations", JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, DOI: 10.1016/ J.JMPS.2018.08.002. The invention is defined in independent claim 1 with further embodiments being specified in the dependent claims 2 to 10. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing will be apparent from the following more particular description of example embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments. FIG. 1 is a block diagram of an engineering design optimization method in which embodiments may be implemented.FIG. 2A is a diagram illustrating accuracy of simulations performed with existing methods.FIG. 2B depicts results of applying a force on real-world objects that may be simulated using computer-based simulation techniques.FIG. 3 is a flowchart of a method for simulating a real-world object according to an embodiment not falling within the scope of t