# Altair Manufacturing Solver 2021.1 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. The current version of Manufacturing Solver includes casting and welding solution modules.

## Metal Casting

### New Features

Parallel MPI Version of Linux Solver
A parallel MPI version of the solver is implemented in this release to support distributed computing on Linux operating system. This implementation also increases the parallel efficiency on shared-memory platforms, which is commonly used.
Casting Modulus using Geometrical Analysis
A new method for computing the casting modulus based on geometric and solidification data is implemented in this release. Data image processing is used to post-process the solidification pattern and then divide the part to compute this modulus.

### Enhancements

Updated Fluid Solver
The casting solver has implemented a new fluid solver that includes a new formulation to impose slip conditions weakly and provides more accurate results in thin to thick transition regions (such as ingates). It also includes a new shock capturing term that improves convergence.
Computation Time
The casting solver will now print the total computational time in the OUT file.
Flow Length Integration Scheme
Now the flow length time integration scheme can be selected. It has been defaulted to Backward Euler that provide more stable solution. (Fixes CCSOL-193)
Piston Shot Volume
The casting solver added an extra check to ensure piston shot volume is enough to fill the part.

### Resolved Issues

Tilt pouring when material properties were not consecutive.
Fixed a bug that was overwriting material IDs when they were not consecutive while performing a tilt pouring simulation. (Fixes CCS-2506)

## Injection Molding

### New Features

Support Models with Molds in Fast Solver
The fast solver supports models with Mold. Including the mold increases the accuracy of the thermal solution. The mold mesh can be a regular tetrahedral mesh.
Parallel MPI Version of the Linux Solver
A parallel MPI version of the solver is implemented in this release to support distributed computing on Linux operating system. This implementation also increases the parallel efficiency on shared-memory platforms, which is commonly used.

### Enhancements

Fiber-Fiber Interaction
The interaction between fibers significantly affects the fiber orientation results. This is now modeled by the solver.
Enhancements to FSI Analysis - Launching OptiStruct
The solver will automatically launch OptiStruct after the injection molding analysis to perform stress analysis.
Enhancements to FSI Analysis - Adding Cooling Stage
In addition to filling and packing, the solver includes the cooling stage also to the FSI analysis. For this stage, there is only the thermal load on the contact surfaces.
Automatic Constraints on Part Inserts for FSI Analysis
Often the part inserts are supported with dynamic constraints that hold them in place until the flow front reaches that location.
Advanced Timestep Control - Variable Time Step
Timestep for each stage (such as filling, packing, and so on) is controlled independently. The solver was supporting automatic timestep control (default) and constant timestep for each stage. In this release, a variable timestep option that can be specified by the user is implemented.
"time_step_settings": {
"time_step_control" : "variable_time_step",
"variable_time_step" : [[0.001,0.0005],[0.1, 0.001], [1.0,0.05]]
}
In the above example, the timestep is controlled as follows:
Analysis Time in a Stage Timestep Value
0.0 - 0.001 0.0005
0.001 - 0.1 0.001
0.1 - 1.0 0.05
1.0 and above 0.05
Advanced Timestep Control - Based on Percentage Volume Fill
The timestep used for simulation can now be varied based on the percentage fill.
"time_step_settings": {
"time_step_control" : "percent_fill_dependent_time_step",
"percent_fill_dependent_time_step" : [[1.0,0.001],[10.0, 0.01], [90.0,0.05], [100.0, 0.001]]
}
In the above example, the timestep is controlled as follows:
% Filled Timestep Value
0.0 - 1.0 0.001
1.0 - 10.0 0.01
10.0 - 90.0 0.05
90.0 - 100.0 0.001
Injection Based on Sensor Control
The solver can now open or close the inlet based on sensor control. This sensor supports control based on flow front location, pressure value, or time.
Synchronizing Inlet With Valve Control
When a full hot runner system is not modeled, each valve can be synchronized with the corresponding inlet. This is achieved by applying the same valve control on the inlet. If this is not done, the solver will crash.

### Resolved Issues

Numerical Roundoff Issue in Clamp Force Value
The clamp force value output in the CSV file and the OUT file did not match due to numerical roundoff. This issue is resolved. (AMSLVR-150)
Logging Error Messages Before Crash
The solver was not writing any error messages when it is terminated due to known exceptions. (AMSLVR-125)
Error in Fiber Orientation Analysis Due to too Many Fibers
The solver was crashing with the message, "Error: Too many fibers are injected with the parameters given." This was due to a bug in the V/P switchover and it is resolved now. (AMSLVER-54)
Update to Clamp Force Calculation
The clamp force prediction in OUT file is updated. (AMSLVR-95)
Incorrect Percent Packing in Some Cases
For a few cases, percent packing was printed incorrectly in OUT file. This issue is resolved. (AMSLVR-159)
Hot Spots in Hot Runner Model
For a few cases, the temperature was shooting up high. This issue is resolved. (AMSLVR-156)

## Welding

### Introduction

The AMS Welding solver is aimed at simulating the typical metal welding processes involving an external heat source such as arc welding and laser welding. It helps the user to virtually design the welding process and gain insights into the quality of the designed process by examining key results such as temperature, distortion, and residual stress. In the release, the AMS Welding solver supports three analysis types: thermal analysis, fast distortion analysis, and coupled analysis.

Thermal Analysis
The AMS Welding solver supports transient thermal analysis of the welding process with temperature-dependent material properties such as conductivity and specific heat. It takes into account the melting and solidification of metals due to the heating and cooling cycles, therefore is able to predict the size of the melt pool and heat-affected zone (HAZ). A set of standard volumetric heat sources are supported, for example: double-ellipsoid and spherical heat sources. Peak temperature and cooling rate results are captured during the welding simulation.
Fast Distortion Analysis
The fast distortion analysis supports fast distortion prediction utilizing an inherent strain-based solution method. It gives quick distortion predictions using linear elastic structural analysis with user-given inherent strain data. The solver also supports the modeling of various filler material deposition sequences to help predict and mitigate overall weld distortion.
Coupled Analysis
The AMS Welding solver supports coupled thermal-mechanical analysis to predict distortion and residual stress induced by temperature gradient during the welding process. The solver supports temperature-dependent thermal material properties and linear thermo-elastic constitutive models.

### New Features

Supported Welding Processes:
• Arc welding
• Laser welding
Supported Physics:
• Transient energy balance equation – heating and cooling of the weldments and workpiece
• Moving volumetric heat source – Goldak double-ellipsoid heat source, and spherical heat source
• User-defined heat source parameters – represent different heat sources involved in arc welding and laser welding processes
• Nonlinear temperature-dependent thermal material properties – density, thermal conductivity, specific heat (Young's modulus and Poisson's ratio are constant for now when solving for displacement.)
• Melting and solidification modeling – accounting for latent heat in thermal solution
• Distortion and residual stress prediction – Static structural solver with linear elastic constitutive law
• Element activation and de-activation – represent adding/removing of filler material; elements are activated with pre-strain, in a stress-free state
• Inherent strain method – Static structural analysis with linear elastic constitutive law and user-defined inherent strain data. Inherent strain includes all inelastic strain contributions.
Supported Results:
• Temperature
• Heat Flux
• Peak Temperature
• Cooling Rate
• Displacement
• Residual Stress