What is additive manufacturing or 3D printing?
Additive manufacturing or 3D printing refers to the process of creating a three-dimensional object using a computer-aided design (CAD) model or digital 3D model. This process involves adding layers of material on top of each other until the final product is formed. It can be accomplished through various methods where materials are joined, deposited, and solidified under computer control. The materials used can include plastics, liquids, or powdered substances that are fused together. A comprehensive description of 3D printing and its modeling in Abaqus is provided in this training package.
Simulation of 3D printing in Abaqus
Why do we need to simulate 3D printing in Abaqus? The reasons are similar to other simulations. It allows us to examine residual stresses, temperature and thermal conditions, deflection in the model, and more. Additionally, it helps us determine if the machine settings are suitable for our model’s conditions before printing, thus avoiding unnecessary costs. Factors such as material properties and temperature need to be considered.
This training package on 3D printing in Abaqus will teach you how to perform this simulation using AM Modeler plug-in (old version). The method utilizes the ADM plug-in developed by Dassault Systemes to simulate the 3D printing process.
Using the AM Modeler plug-in for additive manufacturing
The “AM Modeler” plug-in provides a user-friendly interface for additive manufacturing simulation, minimizing the risk of errors. Unlike Python scripting or coding, this plug-in only requires users to input the necessary data, create a job, and initiate the simulation. The plug-in offers two methods for simulating 3D printing: eigenstrain and thermomechanical. Each method consists of different process types that users can choose from based on their specific requirements. The eigenstrain method includes trajectory-based and pattern-based processes, while the thermomechanical method encompasses trajectory-based powder bed fabrication, pattern-based powder bed fabrication, laser direct energy deposition, and fusion deposition modeling. This training package primarily focuses on the thermomechanical method.
The thermomechanical approach involves conducting a sequential thermal-stress analysis of the additive manufacturing process. It begins with a heat transfer analysis, followed by a static structural analysis that utilizes the temperature fields obtained from the thermal analysis. This simulation provides precise control over processing conditions in terms of time and space, resulting in a comprehensive and realistic solution. However, as the time and spatial resolution increase, the computational cost of the simulation also rises.
The heat transfer analysis within this approach must simulate the progressive material deposition, heating of the deposited material, and cooling of the printed part. The stress analysis is driven by the temperatures obtained from the heat transfer analysis, and similar progressive material deposition methods can be applied. Temperature-dependent material properties can be incorporated to achieve accurate stress results.
Workshop: Sequential thermomechanical analysis of a simple cube using the trajectory-based method with the AM plug-in for LPBF 3D printing
The Laser Powder Bed Fusion (LPBF) method is a 3D printing technique that utilizes a high-powered laser to melt and fuse metal powders layer by layer. In LPBF, a layer of metal powder is spread over a build platform using a roller, and a laser scans the powder, melting and fusing it according to the 3D model. The platform is then lowered, and this layer-by-layer process continues until the object is fully formed.
In this workshop, the geometry of the model and layer details are discussed. Following that, the required material properties and information about the roller and laser beam, including their speeds and “Event series” data, are presented. Boundary conditions are explained, and the modeling process in Abaqus begins. First, modeling is performed using Abaqus/CAE, and then the necessary inputs for the simulation, such as “Event series” data, are added via the AM Modeler plug-in. Two analyses must be conducted: thermal analysis and structural analysis. Finally, the results are analyzed and discussed. This simulation is conducted using an older version of the AM Modeler plug-in.
It would be helpful to see Abaqus Documentation to understand how it would be hard to start an Abaqus simulation without any Abaqus tutorial. Also, be careful with the units of values you insert in Abaqus. Yes! Abaqus don’t have units but the values you enter must have consistent units. You can learn more about the system of units in Abaqus.