Shear imbalance is a tooling gremlin that was often ignored until exposed by John Beaumont about 10 years ago. The causes can be subtle but the problems that result are not. In the last few releases, Autodesk has significantly improved the capability for Autodesk Simulation Moldflow software to evaluate shear imbalance. Last year at AU, Beaumont provided an excellent technical presentation on the subject which resulted in those techniques being adopted by 3D Shapes on projects. Evaluating shear imbalance benefited our customers. We hope by highlighting key points for properly evaluating shear rate and and looking at recent examples, we can now help you benefit from these capabilities too.
Moldflow users, tool designers, molders, and mold shop personnel
Mark is a Mechanical Engineer who began his career in product development including injection molded part design. He has extensive experience with several CAD systems and three plastics analysis packages including C-MOLD and Moldflow. He started 3D Shapes in 1992 as a product development company with an emphasis on FEA. He is EXPERT certified and has used all modules of Moldflow on hundreds of projects including dozens of gas-assist applications. 3D Shapes also uses the Autodesk Mechanical and CFD simulation products.
Analysts working with Autodesk® Simulation Moldflow® software must not only run quality simulations, but also interpret the results and present them clearly. This class is about looking beyond the default plots and customizing the results to improve result clarity for yourself and your audience. Time permitting, you will have a chance to show and discuss your favorite custom plots.
As General Motors relies more on Autodesk® Simulation Moldflow® software for upfront design for manufacturability, it has become apparent that the capability to accurately predict location and relative quality of meld lines is essential to eliminate costly tool re-work—work that is necessary to resolve surface quality and/or part performance issues. A research project was initiated under the auspices of continuous improvement to study the effect of mesh density—relative to obstruction size—on the ability of Moldflow to accurately predict position, length, and quality of a meld line. This class will review the findings of this research by using case studies to illustrate the impact of poor meld-line predictions on tooling strategy and explain how these tooling decisions could have been avoided through meshing technique. Proper mesh density for the accurate prediction of meld-line location and quality will be the next best practice enhancement to the GM Moldflow Specification, GMW16355.
This class has two parts. First, we will review a study on using corrected residual in-molded stress (CRIMS) data to predict warpage. In this study, we selected five parts of increasing complexity and material flow path. We simulated five different materials with various process parameters. From the simulated data, we selected high-warp scenarios for molding and warpage and compared the results with CRIMS and without CRIMS. The study showed the importance and effect of warpage. Statistically, we found that using CRIMS to predict warpage showed a 10 times better probability of being accurate and a 29% improvement in accuracy. Next, we will look at using supplemental data. CRIMS data is specifically measured/generated by Autodesk® Simulation Moldflow® software by molding trails. The test method is expensive. Therefore, for selected materials, we can supplement CRIMS with equivalent material in the existing Moldflow data base. The experiment shows the effectiveness of method.
The Moldflow Sensitivity Study, a design of experiments (DOE), determined the impact of common Autodesk Simulation Moldflow Insight software processing inputs on common results. It also helped to determine the level of interaction among these settings and the impact of material- and geometry-specific interactions. We will highlight the methods used for performing the study, including tcodes, tcodesets, scripts, the Moldflow command shell, creation of studies, modification of studies, extraction of results, and more. Attendees will be able to repeat a similar study with their own commonly used geometries and materials. Study results will help Moldflow Insight users to increase efficiency by reducing design optimization time and determining the magnitude of impact of commonly used process settings. <b>Note:</b> This study included some functionality not currently available in the Moldflow Insight DOE module.
The market for plastic composites is increasing. All types of reinforcements are found, from short to long to continuous fibers. Long-fiber-reinforced plastics can be processed with injection molding and exhibit good performance in energy absorption. This makes them interesting for crash applications for the automotive industry. However, moving to long fibers also means moving towards complexity. Isolated long fibers exhibit a wavy shape, changing stiffness properties of the composite. Straight fibers are found in bundles, influencing the failure of the material. Injection molding of long fibers can lead to fiber breakage. This has to be taken into account when designing plastic parts using simulation. This class provides insight into an approach using DIGIMAT™, with the goal to provide a material model for long-fiber-reinforced plastics. We will present investigations of the material with first approaches to couple structural mechanics with Autodesk Simulation Moldflow software, including prediction of fiber breakage.
Injection mold designers and mold makers are facing increasing challenges due to newly developed molding technologies such as rapid heating and cooling molding (RHCM) or rapid temperature cycle (RTC), as the mold lifecycles could be shorter or uncertain. Even for traditional mold design and making, the lifecycle is typically based on experiences only. We have developed a new tool for mold fatigue analysis. It analyzes the progressive and localized structural damage that causes mold failure due to cyclic loading during the injection molding process. In this class, we will present the complete simulation sequence: transient thermal analysis, mold filling analysis, core-shift analysis, clamping influence, mold stress analysis, and eventually fatigue analysis. This sequence is automated in Autodesk® Simulation Moldflow® Insight software to identify where mold damage could happen first and how many cycles a mold will last.
Compression molding is a process by which pressure is applied to a material by a heat mold. In the case of thermoset elastomers (rubber), the heat and pressure initiate cross linking of the polymer. A specific weight and shape of a material (called a preform) is placed into an open mold, after which the mold halves close. This compression stroke forces the resin to flow and fill out the cavity. After the mold is filled and pressure is applied for a given time (cure time) the mold is split open and the part is removed either by hand or by ejection methods. This process can be applied to both thermoplastic and thermoset materials, both with or without fiber reinforcement. Compression molding simulation can help determine the feasibility and conditions of the manufacturing process, including the size and placement of the preform(s), the internal cavity pressures, and temperatures during the process. These factors enable us to determine how tool and process design affect product quality. During this class, we will discuss an application of compression molding and compare it with compression molding analysis results.
In this class, you will learn about products in the Autodesk Simulation Moldflow software ecosystem that can bring fantastic and unique capabilities to Moldflow products. We will introduce you to capabilities that can help make your job easier, better, and more fun. The class will cover several products, including Autodesk® Simulation 360 cloud-based software and the Autodesk® Inventor® Fusion Technology Preview, which is a free history-free modeler that you can use to make simple changes to existing CAD geometry. We will also cover the Autodesk® Simulation® DFM add-on, which is a designer tool that helps you develop a plastic part that follows standard plastic design rules and can help you avoid time-consuming iterations between the Moldflow user and the CAD designer. You will learn about Autodesk® PLM 360 cloud-based product lifecyle management and Autodesk® Vault, Autodesk® Showcase®, and Autodesk® Inventor® Publisher software. We will also examine Autodesk® Simulation Mechanical software and the tooling capabilities of Autodesk® Inventor® software. Finally, we will introduce you to the Project Simulus Technology Preview from Autodesk Labs.
In this class, you will learn how we used Autodesk Simulation Moldflow Insight Ultimate software to successfully design and develop active-shutter 3D glasses for LCD television. We will focus on the prediction and mitigation of stress birefringence in an optically sensitive injection-molded component. Anyone who is interested in learning more about applying the powerful and specialized modules of Moldflow Insight software in the early stages of product design will gain from this class.
Fiber-reinforced plastic materials provide the means to realize lightweight design and reach CO2 reduction targets. Injection molding helps to reduce costs and to assure a high level of design freedom for the parts. In today's world, each design process is supported by computer simulation, so the performance of the design needs to be investigated in the virtual space. This is typically done by coupling injection molding and structural analyses. To build the necessary procedures, several basic requirements must be met. A good prediction of fiber orientations, a dedicated approach to material modeling with respect to the targeted end performance and quality level of results, as well as a fast and effective mapping procedure for transferring micro-structural information into the environment of the structural analysis are inevitable. To make the coupled approach a success story, each of these points must be understood and respected when setting up the simulation project.
This class will review new functionality in Autodesk® Moldflow® Insight software that represents the current research directions in Moldflow development. We will discuss several capabilities, including 3D injection compression molding, conformal cooling support, 3D heater elements, crystallization analysis, breakage of long fibers and properties of LFT composites, bi-injection molding, multiple cylinder support for 3D gas injection, buckling analysis for 3D warp, improved wall slip calculation, viscoelastic residual stress, ejection force prediction, and analysis of mold fatigue.
Detailed analysis of mold designs is becoming increasingly necessary as advanced mold technologies are adopted. Conformal mold cooling is a cooling technique that aims to offer optimal cooling conditions exactly where you need them. The technology has been around for many years, but has become a real option now with the better and cheaper ways to manufacture conformal cooling cores. Hot runner systems are very commonly used in plastic injection molding. Although these are simple systems on the surface, what actually happens inside the hot runners and how they lose heat into the mold can be quite complex. With the Cool (FEM) functionality inside Autodesk Simulation Moldflow software coupled with Autodesk® Simulation CFD software, you now have the capability to model even the most complicated conformal geometries and hot runners in full three-dimensional detail of all components. This process enables you to evaluate and optimize the hot runner and conformal cooling design to achieve an optimal mold design and injection molding process.