Altair Manufacturing Solver 2023 Release Notes
General
Altair Manufacturing Solver is a state-of-the-art solver suite for manufacturing
applications built on a parallel, modular, and extensible framework that is suitable
for simulations of manufacturing processes. This release contains solutions for the
following modules.
- Additive Manufacturing
- Injection Molding
- Metal Casting
- Polymer Material Data Analytics (PMDA)
- Molding Toolkit
Highlights
Highlights of this release include:
- Additive Manufacturing – A new coarse-scale thermal solver to effectively model the macro-scale heat transfer
- Injection Molding:
- Shell: A new feature to compute the Quality of Fill.
- Fast 3D: A new fast fiber orientation analysis, warpage analysis, and multicycle analysis
- Detailed 3D: Many major new features - Coinjection, multishot molding, multicycle analysis, and cooling channel HTC computation with Flow Simulator are implemented.
- Metal Casting - A procedure to automatically find the contact surfaces between liquid (tet4) and solid (voxel) meshes is implemented in the pre-processing stage and enables accurate specification of interface boundary conditions.
Additive Manufacturing (3DP for SLM)
New Features
- Coarse Scale Thermal Solver
- In metal additive manufacturing simulation, it is crucial to accurately predict the temperature field and thermal gradient evolution during the printing process as they have a direct impact on the distortion and residual stress of the print part. A coarse scale thermal solver has been developed in this release to effectively model the macro scale heat transfer during and after the print process, which provides users with insights on the overall energy balance, temperature distribution as well as potential local hot spots that could cause overheating. It is highly efficient and typically solves the entire printing process in a matter of seconds or minute.
Enhancements
- Body-Fitted Inherent Strain Solver Improvements in Robustness and Performance
- Several improvements have been made to the body-fitted inherent strain solver in this release to enhance its robustness and performance. More specifically, a displacement-based formulation of a ghost penalty method has been implemented to stabilize the cut element being used with the level-set-based structural solver. General improvements to the nonlinear iteration schemes of the structural solver have been made to improve the runtime performance of the solve.
- Improvements in Support Modeling in Body-Fitted Inherent Strain Solver
- In the body-fitted solution, the supports are represented by homogenized voxel mesh. We have improved the accuracy of our homogenization by exact integration of the supports. This would enhance the solution, especially in the residual stress calculation and the support failure results.
- Scaling Factor for Geometry Compensation
- A scaling factor has been implemented as a user-specified option for the geometry compensation process. With such a scaling factor, the user will be able to adjust the magnitude of the final shape of the compensated geometry by comparing the non-scaled compensated shape with experimental data. This feature will provide more flexibility for fine-tuning the desired shape of the printed part. (AMSLVR-742)
Resolved Issues
- Resolved Segmentation Faults in the Collision Detection Process
- The cause for random segmentation faults in the collision detection process has been identified and corrected. This error was happening in the parallelized version of the routine used to collect the element IDs that are out of tolerance and can cause a collision. The issue is addressed by constructing an array of element IDs correctly. (AMSLVR-696)
- Improved Error Message for Recoater collision
- In the previous release, error messages issued by the solver when a recoater collision is detected pointed to an incorrect folder path. There was an error in the solver, where file paths are determined. This issue is now resolved and the messaging has been improved. (INP-1844)
- Clean Exit When Recoater Collides
- In version 2022.3, the solver exits abruptly when it encounters recoater collision without writing the final recoater distance results to the H3D file. Hence, the user cannot check where the collision accident happened. In this release, a new stop criterion has been implemented which checks the elements to be activated beforehand. If it predicts that certain elements will be inverted, the solver stops, and the last step results are written and the solver exits with a proper error message. (AMSLVR-590)
Metal Casting
New Features
- Squeeze Pins
- In this release, material flow through squeeze pins is implemented to reduce porosity. The solver allows to specify a start time and the maximum volume. While the squeeze pin is active and the surface does not become solid, it will reduce the porosity of the liquid clusters connected to the piston. (AMSLVR-665)
- New Preprocessor Before Computing Solution
- The solver now includes a preprocessor to be run locally before launching any calculation and this preprocessor is used to perform manipulations over the provided meshes or geometries.
Enhancements
- Multiple Crucibles for Tilt Pouring
- Users can now select multiple crucibles for the tilt pouring process, defining an initial amount of liquid for each of them. (AMSLVR-739)
- Boundary Conditions Unique to Each Inlet
- Different boundary conditions can be defined for each inlet now. One of the main applications of this enhancement is to be able to select multiple inlets when selecting “Constant liquid level on sprue” in gravity casting. (AMSLVR-670)
- Remove Droplets at the End of Tilt Pouring
- The solver will now remove the droplets at the end o filling in a tilt pouring analysis. This is done in order to ensure that we have a unique volume when we start the solidification stage. If the droplets are bigger than the specified maximum volume (3% of the total volume), removal will be incorrect and the solver will issue an error message. (AMSLVR-732)
- Piston Shot Porosity Compensation in Shot Sleeve Simulations
- The piston can compensate for part of the part contraction as it keeps injecting material during solidification until the gate becomes solid. This compensation was only considered when there was an inlet. Now this is also taken into account in the shot sleeve computations. (AMSLVR-650)
- Use fill time as an Input in Tilt Pouring with Inlet
- In order to specify the velocity in the inlet surface, users can now define the fill time and the solver will internally compute the velocity based on this fill time. (AMSLVR-738)
- Create Liquid Model Parts and Sub-model Parts Internally
- In order to minimize the number of meshing issues, the solver will now create all the liquid model parts and sub-model parts internally. The solver will receive the liquid model parts mesh as a single volume and along with it STL files defining the boundary (skin) of each model part. The solver will organize the mesh into model parts and sub-model parts classifying all the elements and conditions in each corresponding component defined by the STL file. As part of this development, the solver also finds manually the part gates as the intersection of the runner and the part. (AMSLVR-685, AMSLVR-740)
- Liquid–Solid Contact Surfaces Determination in Models Using Voxel Meshes
- A new procedure to automatically find the contact surfaces between liquid and solid meshes is implemented in the pre-processing stage of the solver. This procedure works only in the context of the voxel meshes but allows for robust detection of these contact surfaces between tetrahedral mesh (liquid side) with voxel mesh (solid side) to specify the interface boundary conditions.
Resolved Issues
- Bad Inlet Mesh with Constant Level Filling
- In the analysis of filling with a constant liquid level, the quality of the inlet surface mesh is important and it should have enough free nodes to accurately capture the mass flow. When the inlet mesh is bad we will get incorrect and meaningless results. To avoid this, the solver will check the quality of the inlet mesh and issue a warning message recommending a smaller element size. (AMSLVR-753)
- Mesh with Disconnected Elements and Model Part Name
- There is a check to make sure that all generated elements in the mesh are connected to each other forming a single volume. When an element is not connected to the rest of the volume, now the error message includes the part name. This helps the user identify which component is disconnected and resolve the problem. (AMSLVR-644)
Injection Molding (3D)
The injection molding solver has three complementing solutions addressing the
spectrum of needs of injection molding CAE:
- Detailed 3D (3D) - Requires four or more layers of mesh through the thickness.
- Fast 3D - Also known as Hybrid 3D, it is a powerful solution that requires only one layer of mesh through the thickness.
- Shell - Requires only a surface mesh to compute the solution.
All solvers use the Inspire Mold interface. Refer to the Inspire Mold Release Notes for what is available in the interface.
New Features
- Warpage (Fast 3D)
- The computation of the final shape of the part after it has been ejected
from the mold and cooled down has been added. The method is based on the
same technology used for the other Fast 3D molding solutions (fill,
pack, and cool). The main features of this implementation are:
- Tracking stresses starting from the packing stage
- Ability to compute warpage in disconnected parts at once
- Solve using a coarse mesh with just 1 layer through the thickness
- An equivalent approach to the detailed 3D solution
- Coinjection Molding (3D)
- A new feature is implemented to simulate the coinjection molding process. In this process, two different polymers are injected into the mold cavity from the same inlet to form the out skin and inner core. In this process, the injection happens in a single mold, and the polymers are injected from the same injection point or inlet. And the polymers are injected sequentially if the skin material first and then the core material. Interface support for this feature will be added in a future release. (AMSLVR-706)
- Multicycle Analysis (3D)
- Injection molding is a cyclical process, and the mold temperature attains cyclic steady during the process. The accuracy of the simulation depends on the accuracy of the computed temperature and which in turn depends on the starting mold temperature distribution. In this release, the molding solution has implemented multicycle simulations where the user can perform multiple cooling stages before doing the final filling+packing+cooling+warpage analysis. Performing the cooling stage several times helps to determine the correct molding temperature distribution at the start of the filling stage. (AMSLVR-677)
Enhancements
- Specify Warpage Constraints Using Point Coordinates (3D)
- The warpage analysis requires the part to be constrained such that the rotational degrees of freedom are eliminated. The default is to use the inertia relief wherein the OptiStruct solver handles this internally without constraints in the data deck. In addition, the solver also allowed the user to manually specify the constraints on nodes such that the rotational degrees of freedom are eliminated. In addition to nodes, the user can now specify the constraints by providing the coordinates of the points and the solver will automatically pick the nearest available node to the given coordinates. (AMSLVR-749)
Resolved Issues
- Packing simulation with Mold in MPI (3D)
- The packing simulation with mold had an issue in MPI, now fixed.(AMSLVR-681)
- Air traps and Weld lines prediction (Fast 3D)
- Air traps and weld lines were equal to 0.25, 0.5, or 0.75 on some nodes. A correction has been made and values are now either 0.0 or 1.0 (AMSLVR-752)
Injection Molding (Shell)
New Features
In this release, a new feature to compute the Quality of Fill is implemented.
- Quality of Fill (Shell)
- This estimation is based on shear rate, shear stress, and front temperature rise. This result is categorized into four states: Acceptable, May not be acceptable, Unacceptable, and Short shot. The quality of fill is important and it influences the mechanical properties and the appearance of a part.
(AMSLVR-683)
Enhancements
- Consider Maximum Shear Stress in Molding Window (Shell)
- Shear stress is caused by friction between the moving plastic and the mold wall. It should be less than the critical maximum value for that material. This result determines the indicator of the molding window along with melt front temperature rise and drop, shear rate, pressure, and clamp force. Shear stress is important because it can cause parts to fail if it is too high. (AMSLVR-684)
- Write H3D File to Identify Mesh Issues (Shell)
- While using Inspire Mold for AMS Shell, any issues with generated mesh need a mechanism to visualize, identify, and correct it. To address this, now the shell solver will export an H3D file, and the problem regions in the mesh are highlighted with a sphere. This file is written only when mesh-related issues occur and it will facilitate easier identification of the location of the issues in the mesh and possibly underlying errors in the CAD file. (CMG-2226)
Polymer Material Data Analytics (PMDA)
New Features
- A Module Run Solvers and Extract Results
- A new module to run solvers (Polymer Extrusion and Injection Molding) with all specified materials and a given data deck is implemented. It will automatically update the processing temperatures based on the material data and run the examples in sequence on the local machine. It can also extract key results to a text file.
Resolved Issues
- 1D Runner System - Error in Tapered Cross-section
- There was an error in how the start and end cross-sections of the elements were computed and this issue is resolved now. In addition, any pressure change due to changes in cross-section is considered in the pressure drop computations.
Molding Toolkit
New Features
- Specific Volume (pvT) Fitter
- Specific Volume Fitter (Stand Alone) is added. This will fit pvT data
for most thermoplastic resins. It identifies the following morphology types:
- 0 = Amorphous
- 1 = Semicrystalline
- 2 = Hybrid
- 3 = Polyetherimide (PEI)
Enhancements
- Viscosity Fitter Tolerance to Unequal Temperature Sets
- If the data fed to the Viscosity Fitter had different numbers of shear rates for the different temperature groups, it would crash the fitter. This will be resolved by using cell lists instead of 2D matrices to hold the data being fit.
Resolved Issues
- Warnings Issued Upon Launch of Compose
- A bug was discovered in the launch of the library tied to the viscosity fitter. This has been resolved.