METHODS FOR MODELLING VARIATIONS OF REPEATING PARTS OF A COMPONENT

Abstract

A computer-implemented method for modelling variations of repeating parts of a component is disclosed herein. The method includes providing parameter sets for part configurations of a plurality of different of parts, wherein the parameters of each parameter set respectively define the part configuration of a part; selecting a selection of the part configurations; providing a part model for each part configuration of the selection, wherein the part model relates forces and displacements to locations of the respective part; and building an approximator, wherein the approximator is provided for interpolating the part models to approximate a part model of a part configuration that does not belong to the selection of the part configurations.

Claims

1. A computer-implemented method for modelling variations of repeating parts of a component, the method comprising: providing parameter sets for part configurations of a plurality of different of parts, wherein parameters of each parameter set define a respective part configuration of a part of the plurality of different parts; selecting a selection of the part configurations; providing a part model for each part configuration of the selection, wherein the part model relates forces and displacements to locations of the respective part; and building an approximator, wherein the approximator is provided for interpolating the part models to approximate a part model of a part configuration that does not belong to the selection of the part configurations.

2. The method of claim 1, wherein the providing of the part model comprises: meshing a mesh of the part with solid elements; generating a preliminary part model of the meshed part by relating forces and displacements to locations defining the solid elements through a first part stiffness matrix; identifying constraints reducing a number of exterior degrees of freedom of movement by constrained degrees of freedom; and generating the part model by reducing the model order of the preliminary part model to the remaining exterior degrees of freedom by eliminating the constrained degrees of freedom of the first part stiffness matrix resulting in a reduced stiffness matrix, and wherein the building of the approximator comprises interpolating the reduced stiffness matrixes to extract the reduced stiffness matrix of a part that does not belong to the selection of the part configurations.

3. The method of claim 2, wherein the repeating parts are joints of a lattice structure.

4. The method of claim 3, wherein the selecting of the selection of the part configurations is a random selection.

5. The method of claim 3, wherein the reducing the model order is done using a Guyan reduction resulting in a reduced stiffness matrix.

6. The method of claim 3, wherein the interpolating of the part models uses Canonical Polyadic Decomposition.

7. The method of claim 3, further comprising: generating a reduced component model by using the approximator for several parts of the component; and combining resulting reduced stiffness matrices of the several parts of the component with other models of elements of the component.

8. The method of claim 1, wherein the repeating parts are joints of a lattice structure.

9. The method of claim 1, wherein the selecting of the selection of the part configurations is a random selection.

10. The method of claim 2, wherein the reducing the model order is done using a Guyan reduction resulting in a reduced stiffness matrix.

11. The method of claim 1, wherein the interpolating of the part models uses Canonical Polyadic Decomposition.

12. The method of claim 1, further comprising: generating a reduced component model by using the approximator for several parts of the component; and combining resulting reduced stiffness matrices of the several parts of the component with other models of elements of the component.

13. An additive manufacturing method for generating a component with variations of repeating parts, the method comprising: providing parameter sets for part configurations of a plurality of different of parts, wherein parameters of each parameter set define a respective part configuration of a part of the plurality of different parts; selecting a selection of the part configurations; providing a part model for each part configuration of the selection, wherein the part model relates forces and displacements to locations of the respective part; building an approximator, wherein the approximator is provided for interpolating the part models to approximate a part model of a part configuration that does not belong to the selection of the part configurations; and generating the component using the approximator.

14. A computer system comprising: a processor; and a memory, wherein the memory and the processor are configured to: provide parameter sets for part configurations of a plurality of different of parts, wherein parameters of each parameter set define a respective part configuration of a part of the plurality of different parts; select a selection of the part configurations; provide a part model for each part configuration of the selection, wherein the part model relates forces and displacements to locations of the respective part; and build an approximator, wherein the approximator is provided for interpolating the part models to approximate a part model of a part configuration that does not belong to the selection of the part configurations.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Embodiments of the disclosure are described, by way of example only, with reference to the accompanying drawings, of which:

[0032] FIG. 1 depicts a flow diagram of a method according to an embodiment.

[0033] FIG. 2 depicts a flow diagram of a method according to an embodiment for modelling a component.

[0034] FIG. 3 depicts a flow diagram of a method according to an embodiment for generating an approximator.

[0035] The illustration in the drawings is in schematic form. It is noted that in different figures, similar or identical elements may be provided with the same reference signs.

DETAILED DESCRIPTION

[0036] FIG. 1 depicts schematically a computer-implemented method for modelling variations of repeating parts VRP of a component CMP. The method may include providing parameter sets PRM for part VRP configurations CFG of a plurality of different of parts VRP, wherein the parameters PRM of each parameter set PRM respectively define the part VRP configuration CFG of a part VRP.

[0037] The method may further include selecting a selection SCT of the part VRP configurations CFG.

[0038] The method may further include providing a part VRP model MDL for each part VRP configuration CFG of the selection SCT, wherein the part VRP model MDL relates forces FRC and displacements DPL to locations LCT of the respective part VRP; meshing a mesh MSH of the part VRP with solid elements SOE; generating a preliminary part VRP model PPM of the meshed part VRP by relating forces FRC and displacements DPL to locations LCT defining the solid elements SOE through a first part VRP stiffness matrix SMX; identifying constraints CTS reducing the number of exterior degrees of freedom EDF of movement by constrained degrees of freedom CDF; and generating the part VRP model MDL by reducing the model order ORD of the preliminary part VRP model PPM to the remaining exterior degrees of freedom RDF by eliminating the constrained degrees of freedom CDF of the first part VRP stiffness matrix SMX resulting in a reduced stiffness matrix RSM.

[0039] The method may further include building the approximator APX by interpolating the reduced stiffness matrixes RSM to extract the reduced stiffness matrix of a part VRP that doesn’t belong to the selection SCT of the part VRP configurations CFG.

[0040] The method may further include generating a reduced component model RCP by using the approximator APX for several parts VRP of the component CMP and combining the resulting reduced stiffness matrices of these parts VRP with other models of elements of the component CMP.

[0041] The approximator APX may be considered a Parametrized Superelement PSE.

[0042] FIG. 2 depicts a simplified illustration showing certain acts of the method for modelling a component CMP, herein a lattice structure LTS. The usage of the approximator APX respectively the Parametrized Superelement PSE during lattice simulation, enables the efficient and accurate simulation of, e.g., the diamond lattice DIA shown. The illustration shows the diamond lattice DIA structure being simplified to beams BMS and joints JNT (shown exemplary for one joint JNT). The joint JNT, being a specimen of the general part PRT, is modelled as a Parametrized Superelement PSE and after doing so for all joints JNT the initial diamond lattice DIA structure is modelled. Finally, a reduced overall model OVM is obtained for the component CMP by combining all Parametrized Superelements PSE of the component CMP together with other element of the component. For the application of lattice structure simulation, the method may be part of a procedure which may simulate the beams BMS with 1D elements, but which models the joints JNT as Parametrized Superelements PSE.

[0043] The disclosure is suitable to lattice structural design due to the large number of joints JNT with a complex geometry. The disclosure may also be applied to truss bridges (because such a bridge contains a large number of beams and joints JNT) as well as any structure that contains many parts with a complex geometry (e.g., cars, planes, etc.) which are similar but include variations being defined by the parameter sets PRM for part VRP configurations CFG. Acts of the procedure illustrated include the joint JNT is modelled by meshing it with solid elements constraints CTS are added to reduce the number of exterior degrees of freedom (EDF).

[0044] According to an embodiment, connection faces of joints JNT of a lattice structure may be assumed to remain straight, which may result in a reduced number of remaining exterior degrees of freedom RDF, e.g., in six degrees of freedom per face. A subsequent reduction act may reduce the model order ORD to the exterior degrees of freedom EDF. This may be done by using a Guyan reduction (also known as substructuring, static condensation, etc.) which results in a reduced stiffness matrix similar to what would be achieved by an analytical element but applicable to more difficult geometries. Due to the computationally expensive reduction, a fast approximator APX on basis of a selection SCT of the part VRP configurations CFG may be built to extract the reduced stiffness matrix of a part VRP that doesn’t belong to the selection. For a large number of joint configurations, the reduced matrices are generated. Then, they are interpolated in order to be able to extract the reduced stiffness matrix of a joint with parameters that are not previously simulated. In this case, the Canonical Polyadic Decomposition may be used because it eliminates all parameter dimensions, allowing for a one-dimension (1D) to 1D interpolation (e.g., illustrated in: https://www.tensorlab.net/doc/cpd.html).

[0045] A combination of the above acts enables an efficient calculation of the reduced stiffness matrix RSM that depends on the parameters of the complex geometry it represents.

[0046] FIG. 3 depicts acts of a method. In the method, parameter sets PRM are provided for part VRP configurations CFG a selection SCT of the part VRP configurations CFG is selected as an input IPT for the next act. The method may further include providing a part VRP model MDL for each part VRP configuration CFG by meshing with solid elements SOE, generating a preliminary part VRP model PJM of the meshed part VRP by relating forces FRC and displacements DPL to locations LCT defining the solid elements SOE through a first part VRP stiffness matrix SMX, meshing a mesh MSH of the part VRP with solid elements SOE), and generating a preliminary part VRP model PJM of the meshed part VRP as a first part VRP stiffness matrix SMX)).

[0047] The method may further include constraining with, e.g., the straight face assumption and reducing the remaining exterior degrees of freedom RDF. Higher order face constraints may also be used to make a Parametrized Superelement PSE. For example, 8 external nodes EXN and 6 degrees of freedom (DoF) respectively remaining degrees of freedom (RDF) result in a 48 ×48 stiffness matrix for the Parametrized Superelement PSE.

[0048] The method may further include building a fast approximator APX by repetition of the previous acts and interpolating IPL the reduced stiffness matrixes RSM to extract the reduced stiffness matrix of at least one part VRP that does not belong to the selection SCT of the part VRP configurations CFG. One technique used may be static condensation also known as the superelement approach or substructuring. Afterwards, an interpolation act is required to construct the approximator APX of the reduced stiffness matrix RSM provided as an output OPT of the method. One implementation uses the Canonical Polyadic Decomposition CPD.

[0049] In accordance with various embodiments of the present disclosure, the methods described herein may be implemented by software programs executable by a computer system. Further, in an exemplary, non-limited embodiment, implementations may include distributed processing, component/object distributed processing, and parallel processing. Alternatively, virtual computer system processing may be constructed to implement one or more of the methods or functionality as described herein.

[0050] Although the present specification describes components and functions that may be implemented in particular embodiments with reference to particular standards and protocols, the claim scope is not limited to such standards and protocols. For example, standards for Internet and other packet switched network transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP, HTTPS) represent examples of the state of the art. Such standards are periodically superseded by faster or more efficient equivalents having similar functions. Accordingly, replacement standards and protocols having the same or similar functions as those disclosed herein are considered equivalents thereof.

[0051] A computer program (also known as a program, software, software application, script, or code) may be written in any form of programming language, including compiled or interpreted languages, and it may be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program may be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

[0052] The processes and logic flows described in this specification may be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows may also be performed by, and apparatus may also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0053] As used in this application, the term “circuitry” or “circuit” refers to all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

[0054] This definition of “circuitry” applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term “circuitry” would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term “circuitry” would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in server, a cellular network device, or other network device.

[0055] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and anyone or more processors of any kind of digital computer. A processor may receive instructions and data from a read only memory or a random-access memory or both. Certain elements of a computer include a processor for performing instructions and one or more memory devices for storing instructions and data. A computer may also include or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer may be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio player, a Global Positioning System (GPS) receiver, to name just a few. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., E PROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory may be supplemented by, or incorporated in, special purpose logic circuitry.

[0056] To provide for interaction with a user, embodiments of the subject matter described in this specification may be implemented on a device having a display, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user may provide input to the computer. Other kinds of devices may be used to provide for interaction with a user as well; for example, feedback provided to the user may be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user may be received in any form, including acoustic, speech, or tactile input.

[0057] Embodiments of the subject matter described in this specification may be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a client computer having a graphical user interface or a Web browser through which a user may interact with an implementation of the subject matter described in this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system may be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet.

[0058] The computing system may include clients and servers. A client and server may be remote from each other and may interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

[0059] The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not intended to serve as a complete description of all of the elements and features of apparatus and systems that utilize the structures or methods described herein. Many other embodiments may be apparent to those of skill in the art upon reviewing the disclosure. Other embodiments may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Additionally, the illustrations are merely representational and may not be drawn to scale. Certain proportions within the illustrations may be exaggerated, while other proportions may be minimized. Accordingly, the disclosure and the figures are to be regarded as illustrative rather than restrictive.

[0060] It should be noted that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other acts or elements. Also, elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

[0061] It is to be understood that the elements and features recited in the appended claims may be combined in different ways to produce new claims that likewise fall within the scope of the present disclosure. Thus, whereas the dependent claims appended below depend from only a single independent or dependent claim, it is to be understood that these dependent claims may, alternatively, be made to depend in the alternative from any preceding or following claim, whether independent or dependent, and that such new combinations are to be understood as forming a part of the present specification.

[0062] While the present disclosure has been described above by reference to various embodiments, it may be understood that many changes and modifications may be made to the described embodiments. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting, and that it be understood that all equivalents and/or combinations of embodiments are intended to be included in this description.