Nonlinear Structural Analysis (ANL) extends the capabilities of GPS to include more advanced analysis effects, such as large displacements and permanent material deformation. Material plasticity, typical of metals, can be modeled, as well as the nonlinear elasticity in hyperelastic materials like rubber. ANL also provides more advanced contact capabilities, such as friction at contacting surfaces and the automatic detection of contact surfaces based on their proximity. When ANL is used in conjunction with Thermal Analysis (ATH), a new class of analysis problems can be tackled. Nonlinear structural analysis can be performed including the effects of the temperature distribution calculated by ATH, which can cause parts to expand and contract and also affect their material properties.
- Includes the effects of large displacements and rotations.
- Enables the permanent deformation of materials to be modeled.
- Models the nonlinear elasticity of rubber and other hyperelastic materials.
- Multi-step analysis enables analysis of multiple sequential loadings.
- Provides advanced contact capabilities, such as friction at contacting surfaces.
- Automatically determines contact among parts through the automatic contact detection capability.
- Performs thermal stress analysis when used in conjunction with ATH.
Product Key Customer Benefits
In addition to the functionalities and benefits provided by Generative Part Structural Analysis (GPS), Nonlinear Structural Analysis (ANL) offers:
Basic nonlinear structural analysis
GPS and GAS assume that the response is linear―that the material is linear elastic, that the displacements are small, and that any sliding of surfaces in contact is also small. ANL removes these limitations. It can model the effects of geometric nonlinearity, such as large displacements, and allows nonlinear materials to be included, such as the yielding of metals and nonlinear elastic materials like rubber. It also offers more advanced contact capabilities than GAS, including the ability to model large relative sliding of surfaces in contact.
ANL can model metal plasticity using either isotropic hardening for general use and kinematic hardening for low cycle fatigue studies. For nonlinear hyperelastic materials like rubber a number of different mathematical models are available. The most appropriate model depends on the level of accuracy required and the amount of material test data available. The material properties can be temperature dependent when performing a thermal stress analysis in conjunction with Thermal Analysis (ATH).
ANL enables the effect of multiple steps to be analyzed, where the loading, restraints, contact conditions, etc., vary from one step to the next. This powerful technique allows complex loading sequences to be modeled. For example, a pressure vessel might be subject to an initial bolt tightening step, followed by internal pressurization, and conclude with thermal loading. A step that computes the modes and frequencies of the structure can be included at any point in the loading sequence. Previous loading is important because the natural frequencies can change significantly during deformation as the structure experiences changing loads, boundary conditions, temperature, and contact conditions.
The full range of load types available in CATIA analysis “from concentrated moments to distributed forces to gravity loads” are extended in ANL for nonlinear analysis. The loading can vary over the course of the analysis by referencing an “amplitude.” The loading will follow the motion of the component if it undergoes large displacements or rotations.
ANL offers more advanced connection capability than what is available in GAS. The “Find Interactions” wizard automatically detects pairs of surfaces that will likely come into contact during the analysis, making it easy to set up contact analyses for assemblies. Contacting parts can undergo large relative sliding, which may include frictional effects. Self contact, where a part deforms so much that it contacts itself, can also be included.
A variety of connections can be modeled, such as bolts, springs, and welds. The bolt modeling capability ensures the easy modeling of bolted connections to accurately simulate bolt loads. The spot, seam, and surface weld modeling tools allow a large number of flexible or rigid fasteners to be modeled in just a few steps. Other types of available connections include rigid connections, virtual parts, and nonlinear springs and dashpots.
Robust, efficient solution
ANL uses a state-of-the-art sparse solver that computes the results rapidly while minimizing the amount of memory consumed. It takes full advantage of the additional memory available in 64-bit computers allowing the solution of very large models. A non-symmetric solution is adopted automatically if the problem requires it. Modes and frequencies are calculated using a high performance Lanczos solver.
Nonlinear analysis is performed using an iterative technique that is very robust and requires little user interaction. Load incrementation and convergence is automatic and adaptive and ensures accurate results. Interactive diagnostics help users quickly understand and correct modeling problems.
Contours of various results can be plotted in the part or assembly. X-Y plots also provide a valuable means to view behavior at specific locations. For example, X-Y plots can be created to show force vs. displacement at points of interest in the model.