Computer-implemented method for simulating mold cavity filling process

Abstract

To provide a computer-implemented method for simulating a mold cavity filling process in an injection molding process using a plastic material.SOLUTION: A method comprises the steps of: discretizing at least a portion of a mold cavity into a plurality of cells; defining a cavity injection point (114); determining, for each cell, a surface normal direction perpendicular to the nearest cavity surface; determining a cell coordinate system for each cell defined by a first major direction parallel to a flow direction (120), a third major direction parallel to the normal direction, and a second major direction perpendicular to the first major direction and third major direction; and determining the flow direction (120) of a molding flow for each cell.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a computer-implemented method for simulating the filling process of a mould cavity in an injection moulding process, a method for validating the design of an object, a computer system, a computer program and a database for use in the computer-implemented method. Such a method, system and apparatus may generally be employed for technical design or configuration purposes, for example in the development phase of an injection moulding process, but further applications are possible. [Background technology]

[0002] Injection molding is a common manufacturing method in modern small- and large-scale manufacturing. In a typical injection molding process, plastic materials, such as thermoplastic, thermosetting, or elastomeric materials, are typically melted in a heating process and then injected into an empty die, for example, under pressure. The plastic material then typically hardens in a cooling or curing process to maintain the shape imparted by the die, thereby becoming a product. Products formed by the die can thus be mass-produced. Because die design and construction are expensive, dies cannot be easily modified if any problems occur during injection molding. Therefore, to minimize production costs and waste, the filling process of the die or mold cavity is typically simulated before using common simulation methods.

[0003] Various methods are known for simulating the filling process of a mold cavity in an injection molding process. However, implementing such methods is generally very time-consuming and complex. In particular, such methods usually require complex calculations, e.g., the performance of numerical solutions of complex systems of differential equations. Therefore, such methods generally require large amounts of storage and computing power.

[0004] To reduce the time and resources required to generate an injection molding simulation result set, for example, EP 2612266 B1 describes a method, system, and apparatus, including a computer program encoded on a computer storage medium, for interactively simulating an injection molding model. A three-dimensional CAD model representing an injection molding cavity is identified. The mold cavity includes the location of at least one gate. Potential fill patterns for injecting material into the injection molding cavity are determined. The determined fill pattern is based at least in part on the shape and dimensions of the modeled mold cavity and the location of the at least one gate. A strip model of the CAD model is generated based at least in part on the determined fill pattern. The strip model is used to perform a strip analysis to simulate material injection into the injection molding mold cavity.

[0005] Further, by way of example, EP 1376415A2 describes a method for modeling the injection of a fluid into a mold defining a three-dimensional cavity. The method includes: providing a three-dimensional computer model defining the cavity; discretizing a solution domain based on the model; specifying boundary conditions; and solving for process variables using conservation of mass, conservation of momentum, and conservation of energy for at least a portion of the solution domain. The step of discretizing the solution may include generating a finite element mesh based on the model by subdividing the model into a plurality of connected elements defined by a plurality of nodes; and anisotropically refining the mesh so that there are more nodes in a first direction in which the material properties vary more than in a second direction in which the material properties vary less, the refining including at least one of the substeps of calculating distances from the nodes to the boundaries; and using a node layer numbering system.

[0006] Furthermore, US9919465B1 describes a molding system including a mold having a mold cavity; a molding machine configured to fill the mold cavity with a composite molding resin including a polymeric material having a plurality of fibers; a computing device connected to the molding machine; and a controller connected to the computing device. The computing device includes a processor configured to generate a previous orientation distribution of fibers in the mold cavity based on molding conditions of the molding machine, a rotational diffusion distribution of fibers based on the previous orientation distribution of fibers, and an updated orientation distribution of fibers based on the rotational diffusion distribution of fibers. The controller is configured to control the molding machine to perform actual molding under molding conditions for injecting the composite molding resin into at least a portion of the mold cavity.

[0007] Furthermore, US2008 / 221845A1 describes an apparatus and method for process simulation and structural analysis using hybrid models. For example, the method of the present invention automatically defines a hybrid solution domain by dividing a representation of a plastic part or mold cavity into two parts: one that allows for simplified analysis and one that requires more complex analysis. The method can use any form of CAD data representing the surface of the part or mold as input. Furthermore, the present invention provides a method for simulating fluid flow within a mold cavity by automatically creating a hybrid solution domain, automatically discretizing the domain, and solving for the distribution of process variables within the solution domain.

[0008] US9862133B1 describes a method for preparing an injection-molded fiber-reinforced composite article using a molding machine controlled by a control module connected to the molding machine. The method includes a molding simulation performed by the control module to generate a shear rate distribution of the composite molding resin in a simulation region. The method is then performed by the control module to generate a fiber orientation distribution in the composite molding resin, taking into account the effect of shear rate on fiber-fiber interactions and / or the effect of shear rate on fiber response speed degradation. The controller then controls the molding machine under molding conditions to perform an actual molding in which the composite molding resin is injected into at least a portion of a mold cavity.

[0009] Despite the advantages of modern injection molding simulation methods, several technical challenges remain. For example, simulating the filling process can be very time-consuming and complex, and the required computing power can still be too high. Furthermore, the properties of the manufactured product must be taken into account in addition to the filling pattern and manufacturability. Summary of the Invention [Problem to be solved by the invention]

[0010] It is therefore desirable to provide means and methods that address the above-mentioned technical problem of simulating the filling process of a mold cavity in an injection molding process. Specifically, methods, systems, programs, and databases are proposed for further improving the performance of simulating the filling process of a mold cavity in an injection molding process compared to devices, methods, and systems known in the art. [Means for solving the problem]

[0011] This problem is addressed by a method, a system, a program and a database with the features of the independent claims. Advantageous embodiments, which may be realized independently or in any combination, are set out in the dependent claims.

[0012] When used below, the terms "have," "comprise," or "include," or any grammatical variations thereof, are used in a non-exclusive manner. Thus, these terms can refer both to a situation in which, besides the features introduced by these terms, no further features are present in the entity described in this context, and to a situation in which one or more further features are present. As an example, the expressions "A has B," "A comprises B," and "A includes B" can refer both to a situation in which no other elements are present in A besides B (i.e., a situation in which A solely and exclusively consists of B), and to a situation in which, in addition to B, one or more elements are present in entity A, such as element C, elements C and D, or further elements.

[0013] Furthermore, it should be noted that the terms "at least one," "one or more," or similar expressions indicating that a feature or element may be present more than one time are typically used only once when introducing each feature or element. Note that in most cases hereinafter, when referring to each feature or element, the expressions "at least one" or "one or more" will not be repeated, despite the fact that the feature or element may appear more than one time.

[0014] Furthermore, when used hereinafter, the terms "preferably," "more preferably," "particularly," "more particularly," "particularly," "more particularly," or similar terms are used in connection with any feature without limiting its alternative possibilities. Features introduced by these terms are therefore optional features and are not intended to limit the scope of the claims in any way. The present invention can be practiced using alternative features, as will be recognized by those skilled in the art. Similarly, features introduced by "in one embodiment of the present invention" or similar expressions are intended to be optional features, without any limitations regarding alternative embodiments of the invention, without any limitations regarding the scope of the invention, and without any limitations regarding the possibility of combining features introduced in this way with other optional or non-optional features of the invention.

[0015] In a first aspect of the present invention, a computer-implemented method for simulating the filling process of a mold cavity in an injection molding process with a plastic material is disclosed. The computer-implemented method may also be referred to as a method or a simulation method. The computer-implemented method includes the following steps, which may be performed in a predetermined order, although different orders are possible. Furthermore, one, more than one, or all of the method steps may be performed once or repeatedly. Furthermore, the method steps may be performed overlapping in time or in parallel. The method may further include additional method steps not listed.

[0016] The computer-implemented method includes the following steps: i) discretizing at least a portion of a mold cavity into a plurality of cells; ii) defining a cavity injection point; iii) for each cell, determining a surface normal direction perpendicular to the nearest cavity surface; iv) - a first principal direction parallel to the flow direction; a third principal direction parallel to the normal direction; a second main direction perpendicular to the first main direction and the third main direction; determining a cell coordinate system for each cell, defined by: v) determining the flow direction of the molding flow for each cell; Includes:

[0017] The term "filling process" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. This term may specifically, but not exclusively, refer to a procedure in which at least one material, specifically a formless material such as a liquid or molten material, is injected, forced, or sucked into any collector or container, such as a mold. Accordingly, the term "mold cavity filling process" may refer to a procedure in which a formless material, such as a liquid or a molten mass of a material, is filled into any void of a die or form. In particular, the mold cavity, e.g., the void of a die or form, may be configured to transfer a shape or form to the formless material. Specifically, the "mold cavity filling process in an injection molding method" may refer to a procedure in which a formless material, such as a liquid or a molten mass of a material, is filled into a mold cavity, e.g., the void of a die or form, by injection, specifically by applying pressure to the formless material. Specifically, a molten mass of a plastic material may be used as the formless object.

[0018] The term "plastic material" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term may specifically refer to, without limitation, any thermoplastic, thermosetting, or elastomeric material. In particular, a plastic material may be a mixture of substances including monomers and / or polymers. Specifically, a plastic material may be or include a thermoplastic material. Additionally or alternatively, a plastic material may be or include a thermosetting material. Additionally or alternatively, a plastic material may include an elastomeric material.

[0019] The plastic material may include additional substances such as, for example, a filler material dispersed within the plastic material. In particular, the additional substance may be one or more of any fibers, such as, for example, at least one reinforcing fiber. Specifically, the plastic material may be a fiber-reinforced plastic material. As an example, the fibers dispersed within the plastic material may be fibers having a length L of 0 mm < L ≦ 50 mm, specifically 0 mm ≦ L ≦ 10 mm, more specifically 0.05 mm ≦ L ≦ 1 mm.

[0020] The term "discretization" as used herein is a broad term and should be given its ordinary and customary meaning to those of ordinary skill in the art and should not be limited to a special meaning or a customized meaning. Specifically, without limitation, this term may refer to the process of dividing any predefined space, such as a two-dimensional or three-dimensional form, into a finite number of entities or subspaces. Specifically, at least a part of the mold cavity may be discretized into a plurality of cells.

[0021] The term "cell" as used herein is a broad term and should be given its ordinary and customary meaning to those of ordinary skill in the art and should not be limited to a special meaning or a customized meaning. Specifically, without limitation, this term may refer to an entity or space of any shape, specifically a subspace. A cell may have a surface consisting of a plurality of flat surfaces, and each of the plurality of flat surfaces may simultaneously form at least one flat surface of an adjacent or adjoining cell. Specifically, a cell may have the shape or form of a tetrahedron, a cube, or an octahedron. A cell form with curved edges is also possible. As an example, all of the cells of a plurality of cells may be equal to each other in at least one characteristic of the cell, such as the volume, form, or shape of the cell. Thus, as an example, at least a part of the mold cavity may be discretized into a plurality of cells having the form of a tetrahedron.

[0022] The term "cavity injection point" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term may specifically refer, without limitation, to the location of an entrance through which material enters a cavity during a filling process. In particular, a cavity injection point may be or have at least one hole in a cavity wall through which a molten mass of formless material, e.g., plastic material, can be injected into the mold cavity. Specifically, the flow of material, e.g., plastic material, into the mold cavity may begin at the cavity injection point.

[0023] The term "surface normal direction" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term may specifically, without limitation, refer to a course parallel to a line, where the line is perpendicular to the surface. In particular, the surface normal direction determined for each cell in step iii) may be the surface normal direction of the nearest cavity surface. Specifically, for each cell of the plurality of cells, a surface normal direction perpendicular to the nearest cavity surface may be determined. Thus, for each cell, a cell normal direction perpendicular to the mold cavity surface nearest to the cell may be determined.

[0024] The cell coordinate system determined in step iv) may be assigned to each cell of the plurality of cells. The term "cell coordinate system" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. Specifically, without limitation, the term may refer to a Cartesian coordinate system assigned to a cell. Thus, the cell coordinate system may be a Cartesian coordinate system including three principal directions aligned at right angles to each other, where the first principal direction is parallel to the flow direction, specifically the flow direction of the cell; the third principal direction is parallel to the normal direction, specifically the normal direction of the cell, more specifically the normal direction of the surface or surface cell nearest the cell; and the second principal direction is perpendicular to the first and third principal directions.

[0025] The term "flow direction" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term may specifically refer, without limitation, to the line or course along which any material is moving or about to move. In particular, flow direction may refer to the local direction in which a molten mass of plastic material is moving, for example, in a filling process. Flow direction may specifically refer to the local direction of average mass flow of a molten mass of plastic material, for example, in a filling process. Thus, the first principal direction of the cell coordinate system may be parallel to the direction in which a molten mass of plastic material moves within or through a cell. In particular, the first principal direction of the cell coordinate system may be parallel to the initial direction in which a molten mass of plastic moves within or through a cell when it first enters the cell, particularly in a filling process.

[0026] When the plastic material is a fiber reinforced plastic material, the method comprises: vi) determining the fiber orientation of the fiber reinforced plastic material; It may further include:

[0027] The term "fiber orientation," as used herein, is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically, but without limitation, refer to at least one item of information describing the spatial orientation of fibers in space. Thus, by way of example, the fiber orientation may include at least one angle representing the orientation of the fiber axis of the fiber relative to at least one coordinate system or angular coordinate system. Additionally or alternatively, the at least one item of information may include a vector, such as a unit vector, oriented parallel to the fiber axis of the fiber.

[0028] In particular, step vi) may further comprise evaluating the plastic material used in the injection molding process and, if the plastic material used in the injection molding process is a fiber reinforced plastic material, determining the fiber orientation of the fiber reinforced plastic material.

[0029] Step vi) may further comprise the sub-step vi.1) of providing a database, in particular the database may comprise, for at least one dummy element, information on the fibre orientation of the fibre reinforced plastic material.

[0030] The term "database," as used herein, is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically refer to any collection of information, such as, but not limited to, information stored in at least one data storage device. A database may also include at least one data storage device having information stored therein. In particular, a database may include any collection of information. As an example, a database may include information regarding fiber orientation of a fiber-reinforced plastic material.

[0031] The term "dummy element" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically refer, without limitation, to any object used in analysis or testing. In particular, the dummy element may be created or fabricated for the purpose of analyzing or determining at least one characteristic of the dummy element. Specifically, the dummy element may be configured to provide information, e.g., information regarding at least one characteristic of the dummy element. The dummy element may, for example, include at least one fiber-reinforced plastic material and may be configured to provide information regarding fiber orientation, specifically, information regarding the fiber orientation within the dummy element. Information regarding the fiber orientation within the dummy element may be stored in a database.

[0032] The information included in the database may include, for example, one or both of simulated data and empirically obtained data regarding fiber orientation. Specifically, the information included in the database may include empirically obtained data regarding fiber orientation, such as data obtained using at least one dummy element. Additionally or alternatively, the database may include simulated data regarding fiber orientation, such as data regarding fiber orientation obtained using one or more simulation tools known to those skilled in the art, such as, for example, simulation tools based on the finite element method (FEM) simulation.

[0033] Step vi) may further include a sub-step vi.2) of retrieving information about the fiber orientation of each cell from a database using the cell position of the cell to determine the fiber orientation of the cell in the cell coordinate system.

[0034] The database may be configured such that information regarding the fiber orientation of each cell is obtainable or accessible via information regarding the cell's location, specifically, the database may be configured such that information regarding the cell's location can be linked to information regarding the fiber orientation.

[0035] The cell position is, for example, - the distance of the cell from the center plane of the mold cavity; - the distance of the cell from the central axis of the mold cavity; - the distance of the cell from the nearest cavity surface; - the distance of the cell from the cavity injection point, and The distance may include at least one distance selected from the group consisting of:

[0036] Distances may be given in relative and / or absolute units. Thus, distances may be given in relative distance units, such as number of cells. For example, distances may be given in number of cells from the center plane of the mold cavity, from the central axis of the mold cavity, from the nearest cavity surface, and / or from the cavity injection point.

[0037] Step vi.2) may be performed in particular using consideration of the similarity between the mold cavity and the dummy element, in particular, step vi.2) may be performed using consideration of the similarity between the shape of the mold cavity and the shape of the dummy element.

[0038] As used herein, the term "considering similarity" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term may specifically, but not exclusively, refer to a consideration or evaluation of any similarity or correspondence between at least two objects. This allows, for example, a consideration of similarity to transfer characteristics of a known object to an unknown object. Specifically, similarity, e.g., similarity or correspondence, can be considered between two objects, such as between a mold cavity and a dummy element. Specifically, similarity between at least two objects, e.g., between a mold cavity and a dummy element, can be considered by comparing at least one characteristic, e.g., shape, form, extent, etc., of each of the at least two objects.

[0039] In particular, the similarity consideration can be based on the assumption that, by using similar definitions of the coordinate systems of the mold cavity cells and the dummy elements, for the same relative positions in the mold cavity and the dummy elements, respectively, the fiber orientation in the mold cavity is the same as the fiber orientation in the dummy elements.

[0040] The method may further include determining surface cells of the plurality of cells. In particular, the method may include determining surface cells of the plurality of cells before performing step iii) of the method. In particular, the method may include determining surface cells of the plurality of cells between steps i) and ii) of the method.

[0041] The term "surface cell" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to any cell located or disposed at the outermost portion of any object. In particular, a surface cell may be located at the outer boundary of the shape or form of any object. Thus, as an example, a surface cell of a plurality of cells discretizing a mold cavity may be located, for example, on the surface of the mold cavity. Specifically, a surface cell of a plurality of cells discretizing a mold cavity may include any number of cells located on the surface of the mold cavity.

[0042] The method may further include determining neighboring cells of each individual cell of the plurality of cells. Specifically, the method may include determining neighboring cells of the plurality of cells before performing step v) of the method. More specifically, the method may include determining neighboring cells of each individual cell of the plurality of cells during steps i) and iii) of the method.

[0043] The term "adjacent cells" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. This term may specifically refer to, without limitation, any neighboring or adjacent cell. In particular, an adjacent cell of an individual cell of a plurality of cells may be a cell located adjacent to the individual cell. In particular, each individual cell of a plurality of cells may have multiple neighboring cells.

[0044] The method may further include determining a cell filling sequence using information about neighboring cells. In particular, the information about neighboring cells gathered by determining neighboring cells for each individual cell of the plurality of cells may be used to determine the cell filling sequence. In particular, the cell filling sequence may start from a starting cell, the starting cell being located at the cavity injection point.

[0045] The method may further comprise recursively determining the inflow of molten mass of plastic material from neighboring cells for each individual cell. Thus, in particular, the inflow of molten mass of plastic material from neighboring cells for each individual cell of the plurality of cells may be recursively determined. By way of example, the mass or mass flow balance may be calculated iteratively.

[0046] Further, the method may include recursively solving a continuity equation for each individual cell by considering the inflow and outflow rates from adjacent cells. Specifically, for each individual cell of the plurality of cells, the continuity equation may be recursively solved, for example, by considering the inflow and outflow rates from adjacent cells. The term "continuity equation" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. Specifically, the term may refer to an equation or formula that describes the transport of any quantity, without being limited thereto. In particular, the continuity equation may be based on conservation principles in physics. Specifically, the continuity equation may be based on the principle of conservation of mass. Thus, the continuity equation may consider mass balance. For example, the continuity equation may consider, for any cell, the outflow of molten mass of plastic material to adjacent cells to be equal to the inflow from adjacent cells to that cell minus the molten mass of plastic material remaining in the cell itself.

[0047] The method may further include determining wall thickness information for each cell of the plurality of cells. Specifically, the method may include determining the wall thickness before performing step v). More specifically, the method may include determining the wall thickness between steps iv) and v). As used herein, the term "wall thickness," specifically "wall thickness information," is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. Specifically, the term may refer, without limitation, to the local extension of any element in a direction normal to the surface of the element. Specifically, the wall thickness of a mold cavity may be or include information regarding the extension of the mold cavity in a direction normal to the surface of the mold cavity. Additionally or alternatively, the wall thickness of a mold cavity may be or include information regarding the extension of the mold cavity in a flow direction, specifically, in a direction perpendicular to the flow direction of the molten mass of plastic material during the mold cavity filling process. For example, the wall thickness information for a plurality of cells, particularly for a cell of the plurality of cells that discretize the mold cavity, may be the extension of that cell in a direction normal to the surface of the mold cavity. Additionally or alternatively, the wall thickness information for a plurality of cells, particularly for a cell of the plurality of cells that discretize the mold cavity, may be the extension of the cell in a direction perpendicular to the flow direction, particularly in a direction perpendicular to the flow direction of the molten mass of plastic material. As an example, the wall thickness information for a cell of the plurality of cells may be the extension in a direction normal to the surface of the mold cavity, which extension is further oriented perpendicular to the flow direction of the molten mass of plastic material.

[0048] The method may further include determining a flow front advancement. In particular, the advancement or progression of a flow front of a molten mass of plastic material may be determined. Specifically, the advancement of a flow front of a molten mass of plastic material in a mold cavity can be determined. The term "flow front" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. The term may specifically, without limitation, refer to a front line of moving or advancing fluid or molten material. In particular, the flow front may be or include a front line of a molten mass of plastic material advancing within a mold cavity, for example, during a filling process. The term "flow front advancement" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. The term may specifically, without limitation, refer to a flow front advancement. In particular, the advancement of the flow front may be or may include the advancement of the forward travel of the flow front, such as the advancement of the front of the molten mass of plastic material moving or advancing within the mold cavity during the filling process.

[0049] The step of determining the advancement of the flow front may specifically include determining the flow front velocity. In one example, the flow front velocity is calculated using the following formula:

[0050]

number

[0051] If the determined pressure level is higher than a predetermined pressure threshold, the advancement of the flow front may be stopped. Thus, if the determined pressure level, e.g., a calculated pressure level, exceeds a predetermined pressure threshold, the advancement of the flow front may be terminated. The predetermined pressure threshold may, for example, be similar to the maximum pressure acting on the molten mass of the plastic material during the injection molding process, specifically the maximum achievable pressure.

[0052] The determined pressure level may depend on one or more of the properties of the molten mass of the plastic material used in the injection molding process and the mold geometry. Specifically, the determined pressure level may depend on one or more of the properties of the molten mass of the plastic material used in the injection molding process, such as at least one viscosity of the molten mass of the plastic material, and the mold geometry, such as at least one wall thickness or at least one channel length.

[0053] The method may further include determining a minimum pressure requirement for completely filling the mold cavity with the molten mass of the plastic material. For example, if the plastic material is a fiber-reinforced plastic material, the method may include determining a minimum pressure requirement for completely filling the mold cavity with the fiber-reinforced plastic material. Specifically, determining the minimum pressure requirement may be or may include identifying a minimum pressure value suitable for completely filling the mold cavity with the molten mass of the plastic material.

[0054] The information contained in the database may, for example, comprise data relating to fiber orientation in at least one dummy element having a predetermined thickness, in particular, the fiber orientation may be provided in the database as a function of position within the dummy element.

[0055] Information about fiber orientation: - distance from the center plane of the dummy element; - distance from the central axis of the dummy element; - the distance of the dummy element from the nearest cavity surface; - the distance from the injection point of the dummy element, The distance may be provided to the database as a function of at least one distance selected from the group consisting of:

[0056] The distance may be given in relative units, such as, for example, the number of cells. For example, the distance may be given in cells from the center plane of the dummy element, from the central axis of the dummy element, from the nearest cavity surface of the dummy element, and / or from the injection point of the dummy element.

[0057] The information about fiber orientation may specifically include at least one of the fiber orientation direction and the fiber orientation angle, and in particular, the information about fiber orientation may include one or more of the fiber orientation direction and the fiber orientation angle, specifically the fiber orientation angle in each main direction.

[0058] Additionally, the information about the fiber orientation may include the direction of the fiber orientation in a dummy coordinate system of the dummy element. As an example, the dummy coordinate system is: - a first principal direction parallel to the flow direction in the dummy element, in particular parallel to the central axis of the dummy element; - a third principal direction perpendicular to the surface of the dummy element, in particular perpendicular to the surface of a slab-like dummy element or perpendicular to the extension plane of a slab-like dummy element; a second main direction perpendicular to the first and third main directions; It can be defined by:

[0059] The at least one dummy element may specifically include at least one slab-like element having at least two parallel surfaces. Specifically, at least a portion of the dummy element may have a flat shape, for example, a plate shape or a slice shape, such as a flat rectangular shape. Specifically, the slab-like element may have a rectangular cross section with a width greater than its thickness. In particular, the slab-like element may have a rectangular cross section with a width that is at least two times greater than its thickness. More specifically, the slab-like element may have a rectangular cross section with a width that is at least three or at least four times greater than its thickness.

[0060] The database may specifically include information on the fiber orientations of a plurality of fiber-reinforced plastic materials. Thus, the database may include information on the fiber orientations of at least two, and preferably two or more, fiber-reinforced plastic materials. Furthermore, the database may include information on the fiber orientations of a plurality of fiber-reinforced plastic materials for the same dummy element.

[0061] The method may further include determining weld line cells of the plurality of cells, where at least two flow fronts meet at each of the weld line cells.

[0062] Information about the fiber orientation of the weld line cells can be obtained, for example, from the database provided in step vi.1) of the method.

[0063] The method can further include determining one or more of the filling pressure, flow path length, shear rate, shrinkage, and critical thickness for each cell, specifically the mass accumulation amount.

[0064] As an example, performing at least steps i) to v) of the method requires a processing time T, where 0 s < T ≤ 300 s, specifically 0 s < T ≤ 120 s, more specifically 0 s < T ≤ 60 s, and particularly 0 s < T ≤ 30 s.

[0065] The method comprises: vii) outputting at least one visualization selected from the group consisting of fiber orientation, specifically the direction of fiber orientation; fiber orientation angle, specifically the fiber orientation angle in at least one main direction; filling state, specifically the filling state after a predetermined time; pressure state, specifically the pressure state after a predetermined time; shear rate distribution, specifically the shear rate distribution state after a predetermined time; mass accumulation state; flow path length state; shrinkage state.

[0066] In particular, the visualization can be output through at least one interface or port. The term "interface" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically refer, without limitation, to an item or element forming a boundary configured to transfer information. In particular, an interface may be configured to transfer information, e.g., to send or output information from a computing device, e.g., a computer, to another device. Additionally or alternatively, an interface may be configured to transfer information, e.g., to receive information, to a computing device, e.g., a computer. The interface or port may, in particular, provide a means for transferring or exchanging information. In particular, the interface may provide a data transfer connection, e.g., Bluetooth, NFC, inductive coupling, etc. By way of example, the interface or port may be or include one or more of a network or internet port, a USB port, and a disk drive. The visualization can also be displayed on a visual display.

[0067] In a further aspect of the present invention, a method for validating the design of an object is disclosed. The method may also be referred to as a validation method. The method includes the following steps, which may be performed in a predetermined order, although different orders are possible. Furthermore, one, more than one, or all of the method steps may be performed once or repeatedly. Furthermore, the method steps may be performed overlapping in time or in parallel. The method may further include additional method steps not listed.

[0068] The method comprises the following steps: I. providing CAD data of an object; II. Converting the CAD data of the object into CAD data of a corresponding mold cavity for injection molding the object; III. Selecting at least one plastic material and at least one injection point; IV. Simulating the filling process of the mold cavity using the methods described above or in more detail below, in particular the simulation methods; V. Evaluating the simulation results obtained in step IV; Includes:

[0069] The term "design" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically refer, without limitation, to plans and / or specifications for an object or process. As an example, a design may include the shape of an object and / or other technical details provided in the plan.

[0070] The term "validation," as used herein, is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. Specifically, the term may refer to one or more processes of examining, inspecting, or testing a product or process for compliance with one or more prerequisites or criteria, such as to establish and document that a product, service, or system meets regulatory or technical standards, without limitation. Specifically, design validation may include assessing, for example, by simulation and / or testing, whether the design is suitable for an intended use, e.g., whether the design of an object is compatible with a desired manufacturing process, such as injection molding.

[0071] The verification method specifically comprises, in step IV of the method, using a simulation method as described above or in more detail below. Therefore, for most possible definitions of the terms used herein, reference can be made to the description of the simulation method disclosed in the first aspect of the present invention.

[0072] In step III, the at least one plastic material and the at least one injection point can be selected automatically, for example by an algorithm, however, the at least one plastic material may alternatively be selected by at least one user, in particular by a user using a verification method.

[0073] The simulation results evaluated in step V may be, for example, at least one visualization and may be output via at least one interface or port.

[0074] In a further aspect of the present invention, a computer system is disclosed, comprising at least one processor configured to execute a computer-implemented method for simulating a filling process, such as a simulation method as described above or in more detail below.

[0075] The term "processor" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any special or customized meaning. The term may specifically, but not exclusively, refer to any logic circuitry configured to perform the basic operations of a computer or system. In particular, a processor may be configured to process the basic instructions that run a computer or system. As an example, a processor may include at least one arithmetic logic unit (ALU), at least one floating-point unit (FPU), such as a mathematical coprocessor or numeric coprocessor, multiple registers, specifically registers configured to provide operands to the ALU and store operation results, and memory, such as L1 and L2 cache memories. In particular, a processor may be a multi-core processor. In particular, a processor may be or include a central processing unit (CPU). Additionally or alternatively, a processor may be or include a microprocessor, and thus, in particular, elements of a processor may be included on an integrated circuit (IC) chip.

[0076] By way of example, the computer system may further include at least one or both of a data storage and a memory for storing a database, particularly a data storage and / or a memory for storing the aforementioned database.

[0077] In particular, the data storage or memory may be selected from the group consisting of: internal data storage, e.g., an internal drive or memory; external data storage, e.g., an external drive, an external data server such as a cloud server; portable memory, e.g., a memory stick or portable drive.

[0078] Additionally, the computer system may include at least one interface or port. By way of example, the interface or port may be configured for one or more of: receiving information regarding an injection molding process, where the information relates to one or both of a mold cavity shape and a plastic material used; and outputting information regarding simulation results, in particular outputting at least one visualization.

[0079] In particular, the at least one interface or port may be selected from the group consisting of: a network or internet port, a USB port for inputting information, such as by computer mouse or keyboard; a disk drive.

[0080] In a further aspect of the present invention, a computer program is disclosed. The computer program comprises instructions that, when the program is executed by a computer or a computer system, cause the computer or the computer system to perform a simulation method as described above or in more detail below. In particular, one, more than one, or all of the method steps i) to v) of the simulation method as described above can be performed using a computer or a computer network, preferably by using a computer program. Therefore, for most possible definitions of the terms used herein, reference can be made to the description of the simulation method disclosed in the first aspect of the present invention.

[0081] In a further aspect of the present invention, a verification computer program is disclosed, the verification computer program comprising instructions which, when the program is run by a computer or computer system, cause the computer or computer system to perform at least steps II, IV and V of the verification method as described above or in more detail below. Thus, in particular, the verification computer program comprises a computer program as described above or in more detail below for causing the computer or computer system to perform step IV of the verification method.

[0082] In particular, one or both of the computer program and the verification computer program may be stored on a computer-readable data carrier and / or a computer-readable storage medium. As used herein, the terms "computer-readable data carrier" and "computer-readable storage medium" may in particular refer to non-transitory data storage means such as a hardware storage medium having computer-executable instructions stored thereon. A computer-readable data carrier or storage medium may in particular be or include a storage medium such as a random access memory (RAM) and / or a read-only memory (ROM).

[0083] Further disclosed and proposed herein is a computer program product having program code means for performing one or both of the simulation method and validation method according to the present invention in one or more embodiments disclosed herein when the program is executed on a computer or a computer network. In particular, the program code means may be stored on a computer readable data carrier and / or a computer readable storage medium.

[0084] Further disclosed and suggested herein is a data carrier having a data structure stored thereon, which, after being loaded into a computer or computer network, for example into a working memory or main memory of the computer or computer network, can perform one or both of the simulation method and the validation method according to one or more embodiments disclosed herein.

[0085] Further disclosed and suggested herein is a computer program product comprising program code means stored on a machine-readable carrier for performing one or both of the simulation method and the validation method according to one or more embodiments disclosed herein when the program is executed on a computer or a computer network. As used herein, a computer program product refers to a program as a tradeable product. The product may generally exist in any form, for example in paper form or on a computer-readable data carrier. In particular, the computer program product can be distributed over a data network.

[0086] In a further aspect of the present invention, a database for use in the simulation method is disclosed. The database contains information about the fiber orientation of a fiber-reinforced plastic material for at least one dummy element. In particular, the database may be a database as provided in step vi.1) of the simulation method. Therefore, for most possible definitions of the terms used herein, reference can be made to the description of the simulation method disclosed in the first aspect of the present invention.

[0087] The methods, systems, programs, and databases of the present invention have many advantages over methods, systems, programs, and databases known in the art. In particular, the methods, systems, programs, and databases disclosed herein can improve the performance of simulating the mold cavity filling process in an injection molding process compared to devices, methods, and systems known in the art. Specifically, the present invention can significantly reduce processing time, e.g., execution time. Furthermore, the present invention may require less computing power and memory requirements than current state-of-the-art injection molding simulation methods. Also, less effort is required to prepare a simulation model.

[0088] In particular, assigning a cell coordinate system to each cell, as determined in step iv) of the computer-implemented method for simulating the filling process of a mold cavity in an injection molding process with plastic materials, can significantly reduce the computation time. In particular, the cell coordinate system determined for each cell can directly significantly reduce the time required to determine the fiber orientation tensor.

[0089] In summary, and without excluding further possible embodiments, the following embodiments can be envisaged: Embodiment 1: A computer-implemented method for simulating a filling process of a mold cavity in an injection molding process using a plastic material, said method comprising: i) discretizing at least a portion of the mold cavity into a plurality of cells; ii) defining a cavity injection point; iii) for each cell, determining a surface normal direction perpendicular to the nearest cavity surface; iv) - a first principal direction parallel to the flow direction; a third principal direction parallel to the normal direction; a second main direction perpendicular to the first main direction and the third main direction; determining a cell coordinate system for each cell, defined by: v) determining the flow direction of the molding flow for each cell; A method comprising: Embodiment 2: When the plastic material is a fiber reinforced plastic material, the method further comprises: vi) determining the fiber orientation of said fiber reinforced plastic material; 3. The method according to the preceding embodiment, further comprising: Embodiment 3: Step vi) is: A method according to the preceding embodiment, comprising the step of: vi.1) providing a database, said database containing information regarding the fiber orientation of said fiber reinforced plastic material for at least one dummy element. Embodiment 4: A method according to the preceding embodiment, wherein the information contained in the database includes one or both of simulated data or empirically obtained data regarding fiber orientation. Embodiment 5: Step vi) comprises: vi.2) Retrieving information about the fiber orientation of each cell from the database using the cell position of the cell to determine the fiber orientation of the cell in a cell coordinate system. Embodiment 6: The location of the cell is: - the distance of the cell from the center plane of the mold cavity; - the distance of the cell from a central axis of the mold cavity; - the distance of the cell from the nearest cavity surface; - the distance of the cell from the injection point of the cavity; Embodiment 7: The method according to the preceding embodiment, wherein the distance is given in relative units. Embodiment 8: A method according to any one of the preceding three embodiments, wherein step vi.2) is performed using consideration of the similarity between the mold cavity and the dummy element, in particular consideration of the similarity between the shape of the mold cavity and the shape of the dummy element. Embodiment 9: A method according to the preceding embodiment, wherein the consideration of the similarity is based on the assumption that for the same relative positions in the mold cavity and the dummy element, respectively, the fiber orientation in the mold cavity is the same as the fiber orientation in the dummy element, by using a definition of similarity between the coordinate systems of the mold cavity cell and the dummy element. Embodiment 10: A method according to any one of the preceding embodiments, wherein the method further comprises determining surface cells of the plurality of cells, specifically before performing step iii), more specifically between steps i) and ii). Embodiment 11: A method according to any one of the preceding embodiments, wherein the method further comprises determining neighboring cells for each individual cell of the plurality of cells, specifically before performing step v), more specifically between steps i) and iii). Embodiment 12: The method according to the preceding embodiment, wherein the method further comprises determining a cell filling sequence using information about the neighboring cells. Embodiment 13: The method according to the preceding embodiment, wherein the cell filling sequence begins with a starting cell, the starting cell being located at the cavity injection point. Embodiment 14: A method according to any one of the two preceding embodiments, wherein the method includes recursively determining for each individual cell the inflow of molten mass of plastic material from adjacent cells. Embodiment 15: A method according to any preceding embodiment, wherein the method includes recursively solving the continuity equation for each individual cell by considering inflows from and outflows to adjacent cells. Embodiment 16: A method according to any one of the preceding embodiments, wherein the method further comprises determining wall thickness information for each of the plurality of cells, specifically before performing step v), more specifically between steps iv) and v). Embodiment 17: A method according to any one of the preceding embodiments, wherein the method further comprises determining an advance of the flow front. Embodiment 18: The method according to the preceding embodiment, wherein the step of determining the advancement of the flow front comprises determining a flow front velocity. Embodiment 19: The flow front velocity v is calculated according to the following formula:

[0090]

number

[0082] Embodiment 24: The information regarding fiber orientation comprises: - the distance from the center plane of said dummy element; - the distance from the central axis of the dummy element; - the distance of said dummy element from the nearest cavity surface; the distance of the dummy element from the injection point; 21. The method according to any one of the preceding 21 embodiments, wherein the distance is provided to the database as a function of at least one distance selected from the group consisting of: Embodiment 25: The method according to any one of the preceding embodiments, wherein the distance is given in relative units.Embodiment 26: The method according to any one of the preceding 23 embodiments, wherein the information about the fiber orientation includes at least one of a fiber orientation direction and a fiber orientation angle, specifically a fiber orientation angle in each main direction. Embodiment 27: A method according to the preceding embodiment, wherein the information regarding the fiber orientation includes a direction of the fiber orientation in a dummy coordinate system of the dummy element. Embodiment 28: The dummy coordinate system is: - a flow direction within the dummy element, in particular a first main direction parallel to the central axis of the dummy element; - a third main direction perpendicular to the surface of the dummy element, in particular perpendicular to the surface of a slab-like dummy element or perpendicular to the extension plane of the slab-like dummy element; a second main direction perpendicular to the first main direction and the third main direction; 2. The method according to the preceding embodiment, wherein: Embodiment 29: The method according to any one of the preceding 26 embodiments, wherein the at least one dummy element includes at least one slab-like element having at least two parallel surfaces. Embodiment 30: The slab-shaped element has a rectangular cross-section, where the width is at least twice greater than the thickness, more preferably at least three or at least four times greater than the thickness, according to the method of the preceding embodiments. Embodiment 31: The database includes information regarding the fiber orientation of a plurality of fiber reinforced plastic materials, according to the method of any one of the preceding 28 embodiments. Embodiment 32: The database includes information regarding the fiber orientation of a plurality of fiber reinforced plastic materials for the same dummy element, according to the method of any one of the preceding 29 embodiments. Embodiment 33: The method further includes determining the weld line cells of the plurality of cells, where at least two flow fronts meet at each of the weld line cells, according to the method of any one of the preceding embodiments. Embodiment 34: The information regarding the fiber orientation of the weld line cells is obtained from the database provided in step vi.1), according to the methods of Embodiment 33 and Embodiment 3. Embodiment 35: The method further includes determining one or more of the filling pressure, flow path length, shear rate, shrinkage, and critical thickness of each cell, specifically the mass accumulation, according to the method of any one of the preceding embodiments. Embodiment 36: Executing at least steps i) - v) of the method requires a processing time T, where 0 seconds < T ≤ 300 seconds, specifically 0 seconds < T ≤ 120 seconds, more specifically 0 seconds < T ≤ 60 seconds, particularly 0 seconds < T ≤ 30 seconds, according to the method of any one of the preceding embodiments. Embodiment 37: The method: vii) further includes outputting at least one visualization selected from the group consisting of fiber orientation, specifically the direction of fiber orientation; fiber orientation angle, specifically the fiber orientation angle in at least one main direction; filling state, specifically the filling state after a predetermined time; pressure state, specifically the pressure state after a predetermined time; shear rate distribution, specifically the shear rate distribution state after a predetermined time; mass accumulation state; flow path length state; shrinkage state, according to the method of any one of the preceding embodiments. Embodiment 38: The method according to the preceding embodiment, wherein the visualization is output via at least one interface or port. Embodiment 39: A method for validating a design of an object, comprising: The method comprises: I. providing CAD data of the object; II. Converting the CAD data of the object into CAD data of a corresponding mold cavity for injection molding the object; III. Selecting at least one plastic material and at least one injection point; IV. Simulating the filling process of the mold cavity using a method according to any one of the preceding embodiments; V. Evaluating the simulation results obtained in step IV; A method comprising: Embodiment 40: A method according to the preceding embodiment, wherein the simulation result evaluated in step V is at least one visualization output via at least one interface or port. Embodiment 41: A computer system including at least one processor configured to execute a computer-implemented method for simulating a filling process according to any one of embodiments 1 to 38. Embodiment 42: A computer system according to any preceding embodiment, wherein the computer system includes at least one or both of a data storage or a memory for storing a database. Embodiment 43: A computer system according to the preceding embodiment, wherein the data storage or the memory is selected from the group consisting of: internal data storage, e.g., an internal drive or memory; external data storage, e.g., an external drive, an external data server such as a cloud server; portable memory, e.g., a memory stick or portable drive. Embodiment 44: A computer system according to any one of the preceding three embodiments, wherein the computer system comprises at least one interface or port. Embodiment 45: A computer system according to the preceding embodiment, wherein the interface or the port is configured for one or more of: receiving information regarding an injection molding method, the information regarding one or both of the shape of the mold cavity and the plastic material used; and outputting information regarding the simulation results, in particular outputting at least one visualization. Embodiment 46: A computer system according to the preceding embodiment, wherein the at least one interface or port is selected from the group consisting of: a network or internet port, e.g., a USB port for inputting information by a computer mouse or keyboard; a disk drive. Embodiment 47: A computer program comprising instructions that, when the program is executed by a computer or a computer system, cause the computer or the computer system to perform a method according to any one of embodiments 1 to 38. Embodiment 48: A database for use in a method according to any one of embodiments 1 to 38, comprising information on the fiber orientation of a fiber-reinforced plastic material for at least one dummy element. [Brief explanation of the drawings]

[0091] Further optional features and embodiments are disclosed in more detail in the description of the following embodiments, preferably in connection with the dependent claims, where each optional feature may be realized separately and in any possible combination, as understood by a person skilled in the art. The scope of the present invention is not limited by the preferred embodiments. The embodiments are illustrated schematically in the figures, in which identical reference numbers in these figures indicate identical or functionally interchangeable elements. [Figure 1]1 shows a perspective view of an embodiment of CAD data for an object and a corresponding embodiment of a mold cavity for injection molding the object. [Figure 2] 2 illustrates a cross-sectional view of a portion of an embodiment of CAD data for an object and a corresponding embodiment of a mold cavity shown in FIG. 1. [Figure 3] 1A-1C show perspective views of different embodiments of a mold cavity. [Figure 4] 1A-1C show perspective views of different embodiments of a mold cavity. [Figure 5] 1 illustrates a perspective view of an embodiment of a database. [Figure 6] 1 illustrates a perspective view of an embodiment of a computer system. [Figure 7A] 3 shows a flowchart of a different embodiment of a simulation method; [Figure 7B] 3 shows a flowchart of a different embodiment of a simulation method; [Figure 8] 1 shows a flowchart of one embodiment of a verification method. [Figure 9] 1 illustrates a cross-sectional view of one embodiment of a mold cavity for an injection molding process using a plastic material. [Figure 10] FIG. 1 illustrates a top view of a portion of one embodiment of a discretized mold cavity in an injection molding process using a plastic material. [Figure 11] 1A-1C illustrate perspective views of an embodiment of a filling process of a mold cavity in an injection molding method using a plastic material. DETAILED DESCRIPTION OF THE INVENTION

[0092] Detailed Description of the Embodiments FIG. 1 illustrates, in perspective view, one embodiment of CAD data for an object 110 and a corresponding embodiment of a mold cavity 112 for injection molding the object. For illustrative purposes, a mold 113 having a cavity in the shape of the mold cavity 112 is partially shown. A cavity injection point 114 may be defined on the mold cavity 112. FIG. 2 illustrates a cross-sectional view of a portion of the mold cavity 112 illustrated in FIG. 1. The mold cavity 112 may be discretized into a plurality of cells 116. Each cell 116 may include a cell coordinate system. The cell coordinate system may be defined by a first principal direction 118 parallel to a flow direction 120, as illustrated in FIG. 1. Furthermore, the cell coordinate system may be defined by a third principal direction 122 parallel to a surface normal direction 124, which may be oriented perpendicular to the nearest cavity surface 125, as illustrated in FIG. 2. Finally, the cell coordinate system may be defined by a second major direction 126 that is perpendicular to the first major direction 118 and the third major direction 122 .

[0093] 3 and 4, different embodiments of mold cavities 112 are illustrated along with cavity injection points 114. In particular, each mold cavity 112 may be discretized into a number of cells 116.

[0094] 5 illustrates one embodiment of the database 128. The database 128 includes information regarding the fiber orientation of a fiber-reinforced plastic material for at least one dummy element 130. Specifically, as illustrated in FIG. 5, the database 128 may include information regarding the fiber orientation of a fiber-reinforced plastic material for two or more, e.g., three, dummy elements 130. In particular, the information included in the database 128 may include one or both of simulated data and empirically obtained data regarding the fiber orientation of the fiber-reinforced plastic material of the dummy element 130.

[0095] FIG. 6 illustrates an embodiment and perspective view of a computer system 132. The computer system 132 includes at least one processor 134 configured to execute a computer-implemented method for simulating a filling process, such as a simulation method 136. Flowcharts of different embodiments of the computer-implemented method 136 for simulating a filling process, particularly the simulation method 136, are illustrated in FIGS. 7A and 7B. The computer system 132 may include data storage 138, such as for storing the database 128. Furthermore, the computer system 132 may include at least one interface 140. The interface 140 may be configured to receive information related to the shape of the mold cavity 112. Additionally or alternatively, the interface 140 may be configured to output information related to the simulation results, such as a visualization 142.

[0096] A computer-implemented method 136 for simulating the filling process of a mold cavity 112 in an injection molding process with a plastic material, specifically the simulation method 136, includes the following steps, which may specifically be performed in a predetermined order, although different orders are possible. Also, two or more method steps may be performed fully or partially simultaneously. Furthermore, one, more than one, or all method steps may be performed once or repeatedly. The method may further include additional method steps not listed herein. The method steps of the simulation method 136 are the following steps: Step i) (denoted by reference numeral 144) discretizing at least a portion of the mold cavity 112 into a plurality of cells 116; Step ii) defining the cavity injection point 114 (denoted by reference numeral 146); step iii) (denoted by reference numeral 148) determining for each cell 116 the surface normal direction 124 perpendicular to the nearest cavity surface 125; Step iv) (denoted by reference number 150) a first main direction 118 parallel to the flow direction 120; a third main direction 122 parallel to the normal direction 124; a second main direction 126 perpendicular to the first main direction 118 and the third main direction 122; determining a cell coordinate system for each cell 116 defined by: Step v) (indicated by reference numeral 152) determining the molding flow direction 120 of each cell 116.

[0097] Furthermore, the simulation method 136 may include a step vi) (indicated by reference numeral 154) which, if the plastic material is a fiber reinforced plastic material, includes determining the fiber orientation of the fiber reinforced plastic material.

[0098] 7B , an embodiment of the simulation method 136 may further include a branch point 156. The branch point 156 may indicate a conditional query, such as deciding between a first branch 158 and a second branch 160. For example, the conditional query may utilize information about the plastic material, such as information about whether the plastic material is a fiber-reinforced plastic material. The first branch 158 may indicate that the plastic material is a fiber-reinforced plastic material or that the plastic material includes a fiber-reinforced plastic material, and thus the first branch may proceed to step vi) 154. The second branch 160 may indicate that the plastic material does not include a fiber-reinforced plastic material.

[0099] Step vi) 154 may in particular comprise a sub-step vi.1) (denoted by reference numeral 162) of providing a database 128 containing information on the fiber orientation of the fiber reinforced plastic material for at least one dummy element 130. Step vi) 154 may further comprise a sub-step vi.2) (denoted by reference numeral 164) of retrieving information on the fiber orientation of each cell 116 from the database 128 using the cell position of the cell 116 and determining the fiber orientation of the cell 116 in a cell coordinate system.

[0100] In particular, sub-step vi.1) 164 may be performed with consideration of the similarity between the mold cavity 112 and the dummy element 130. In particular, sub-step vi.2) 164 may be performed with consideration of the similarity between the shape of the mold cavity 112 and the shape of the dummy element 130.

[0101] The simulation method 136 may further comprise step vii) (denoted by reference numeral 166) of outputting at least one visualization 142, the visualization 142 being selected from the group consisting of: fiber orientation, in particular the fiber orientation direction; fiber orientation angle, in particular the fiber orientation angle in at least one main direction; filling state, in particular the filling state after a predetermined time; pressure state, in particular the pressure state after a predetermined time; shear rate distribution, in particular the shear rate distribution state after a predetermined time; mass accumulation state; flow path length state; contraction state.

[0102] In particular, step vi) 166 may be performed after performing step vi). Alternatively, if the plastic material does not include a fiber-reinforced plastic material, step vi) 154 of the simulation method 136 may be skipped. Thus, as an example, step vii) 166 may be performed directly after performing step v) 152 by having a second branch 160 lead directly to step vii) 166 of the simulation method 136, as shown in FIG. 7B.

[0103] Specifically, executing the simulation method 136 may require processing time T, e.g., execution time. As an example, Table 1 shows a comparison of execution times for performing a filling simulation of three different mold cavities 112. In particular, the execution time T required to perform a filling simulation using injection molding process simulation methods known to those skilled in the art, such as using FEM simulation, can be calculated. State_of_the_art , the execution time T required to execute the simulation method 136 proposed in this specification. sim Specifically, in the comparison of execution times shown in Table 1, the second column of Table 1 shows the execution time T State_of_the_art and T in the third column. sim , which can be shown to be the run time for three different mold cavities 112, and in particular for the three different embodiments of the mold cavity 112 illustrated in Figures 1, 3, and 4. The mesh size used to run the filling simulations can be 2.0 mm for all three mold cavities 112. The fourth column of Table 1 can list the performance improvement, which can be calculated as the run time T required to run a single filling simulation using an injection molding process simulation method as known to those skilled in the art. State_of_the_art The absolute number of times the simulation method 136 can be executed within a certain time period can be indicated.

[0104] [Table 1]

[0105] 8 shows a flowchart of one embodiment of a method for validating the design of object 110, specifically verification method 168. Verification method 168 includes the following steps, which may be performed specifically in a predetermined order, although different orders are possible. Also, two or more method steps may be performed in whole or in part simultaneously. Furthermore, one, more than one, or all method steps may be performed once or repeatedly. The method may further include additional method steps not listed herein.

[0106] The method steps of the verification method 168 are as follows: Step I. Providing CAD data of the object 110 (denoted by reference numeral 170); Step II. (denoted by reference numeral 172) converting the CAD data of the object 110 into CAD data of a corresponding mold cavity 112 for injection molding the object 110; Step III. Selecting at least one plastic material (denoted by reference numeral 174) and at least one injection point 114; Step IV. Simulating the filling process of the mold cavity 112 using the simulation method 136 (denoted by reference numeral 176); Step V. (indicated by reference numeral 178) evaluating the simulation results obtained in Step IV 176; is.

[0107] In particular, the simulation results evaluated in step V may be at least one visualization 142 output via at least one interface 140, for example as illustrated in FIG.

[0108] 9, a cross-sectional view of one embodiment of a mold cavity 112 for injection molding with a plastic material is shown. In particular, FIG. 9 shows a visual derivation of the physical equation, Equation (1), e.g., as described above, highlighting the link between the velocity v and thickness h of the flow front 180 of the molten mass of the plastic material, the viscosity η of the molten mass of the plastic material, the fill pressure p1, the ambient pressure p0, and the distance l from the flow front 180 to the cavity injection point 114.

[0109] 10 illustrates a portion of one embodiment of a discretized mold cavity 112 for injection molding with a plastic material. In particular, FIG. 10 may illustrate a topological approach to the filling process, specifically, the filling process of a molten mass of plastic material filling the mold cavity 112, starting from the cavity injection point 114 and spreading from one cell 116, specifically from the starting cell 182, to its neighboring cell 184, as shown by the arrows in FIG.

[0110] 11, a perspective view of the filling process of one embodiment of a mold cavity 112 during injection molding with a plastic material is shown. In particular, four filling stages of the mold cavity 112 during injection molding are shown, progressing from left to right as indicated by the x-axis showing the progression of time t at the bottom of FIG. 11. In particular, a flow front 180 can progress through the mold cavity 112 using a blend of topological and physical approaches. [Explanation of symbols]

[0111] 110 Object 112 Mold cavity 113 Die 114 Cavity Injection Point 116 cells 118 1st principal direction 120 Flow direction 122 3rd principal direction 124 Normal Direction 125 Cavity Surface 126 2nd principal direction 128 databases 130 dummy elements 132 Computer Systems 134 processors 136 Simulation Method 138 Data Storage 140 Interface 142 Visualization 144 Step i) 146 Step ii) 148 Step iii) 150 Step iv) 152 Step v) 154 Step vi) 156 Branching Point 158 First Branch 160 Second Branch 162 Step vi.1) 164 Step vi.2) 166 Step vii) 168 Verification Method 170 Step I. 172 Step II. 174 Step III. 176 Step IV. 178 Step V. 180 Flow Front 182 starting cell 184 adjacent cells

[0112] References EP2612266B1

Claims

1. 1. A computer-implemented method for simulating a filling process of a mold cavity (112) in an injection molding process with a plastic material, the method comprising: i) discretizing at least a portion of the mold cavity (112) into a plurality of cells (116); ii) defining a cavity injection point (114); iii) for each cell (116), determining a surface normal direction (124) perpendicular to the nearest cavity surface (125); iv) - a first main direction (118) parallel to the flow direction (120); a third main direction (122) parallel to said normal direction (124); a second main direction (126) perpendicular to said first main direction (118) and to said third main direction (122); determining a cell coordinate system for each cell (116) defined by: v) determining said flow direction (120) of the molding flow of each cell (116); 11. A computer-implemented method comprising:

2. When the plastic material is a fiber reinforced plastic material, the method comprises: vi) determining the fiber orientation of said fiber reinforced plastic material; The method of claim 1 further comprising:

3. wherein step vi) comprises: vi. 1) providing a database (128), said database (128) containing information regarding fiber orientation of said fiber reinforced plastic material for at least one dummy element (130).

4. The method of claim 3 , wherein the information contained in the database (128) includes one or both of simulated data and empirically obtained data regarding fiber orientation.

5. Step vi) comprises: vi.2) using the cell locations of the cells (116) to obtain information about the fiber orientation of each cell (116) from the database (128) to determine the fiber orientation of the cells (116) in a cell coordinate system.

6. 6. The method of claim 5, wherein step vi.2) is performed using a consideration of similarity between the mold cavity (112) and the dummy element (130).

7. 7. The method of claim 6, wherein the consideration of similarity is based on an assumption that, for the same relative position in the mold cavity (112) and the dummy element (130), a fiber orientation in the mold cavity (112) is the same as a fiber orientation in the dummy element (130) by using a definition of similarity of coordinate systems of a cell (116) of the mold cavity (112) and the dummy element (130).

8. The method of any one of claims 1 to 7, wherein the method further comprises determining neighboring cells (184) of each individual cell (116) of the plurality of cells.

9. The method of claim 8, further comprising using information about the neighboring cells (184) to determine a cell filling sequence.

10. The method of claim 9, wherein the method includes recursively determining for each individual cell (116) an inflow of molten mass of plastic material from the adjacent cells (184).

11. 11. The method of claim 10, wherein the method includes recursively solving a continuity equation for each individual cell (116) by considering inflows from and outflows to adjacent cells (184).

12. The method of any one of claims 3 to 11, wherein the database (128) contains information about fiber orientation of a plurality of fiber reinforced plastic materials.

13. 13. The method according to any one of claims 1 to 12, wherein the method further comprises determining wall thickness information for each of the cells of the plurality of cells, in particular before performing step v), more particularly between steps iv) and v).

14. 14. The method according to any one of claims 1 to 13, wherein performing at least steps i) to v) of the method requires a processing time T, where 0 s<T≦300 s, in particular 0 s<T≦120 s, more in particular 0 s<T≦60 s, in particular 0 s<T≦30 s.

15. The method comprises: vii) outputting at least one visualization (142), said visualization (142) being output via at least one interface (140) or port.

16. A method for validating a design of an object (110), comprising: The method comprises: I. Providing CAD data for the object (110); II. Converting the CAD data of the object (110) into CAD data of a corresponding mold cavity (112) for injection molding the object (110); III. Selecting at least one plastic material and at least one injection point (114); IV. Simulating the filling process of the mold cavity (112) using the method of any one of claims 1 to 15; V. Evaluating the simulation results obtained in step IV; A method comprising:

17. 17. The method of claim 16, wherein the simulation result evaluated in step V is at least one visualization (142) output via at least one interface (140) or port.

18. 17. A computer system (132) including at least one processor (134) configured to execute the computer-implemented method of simulating a filling process of claim 16.

19. A computer program comprising instructions that, when the program is executed by a computer or computer system (132), cause said computer or computer system (132) to carry out the method of any one of claims 1 to 17.

20. A database (128) for use in the method of any one of claims 1 to 17, said database (128) containing information about the fiber orientation of a fiber-reinforced plastic material for at least one dummy element (130).

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