Static, Transient, and Frequency-Domain Structural Analysis

The Structural Mechanics Module is dedicated to the analysis of mechanical structures that are subject to static or dynamic loads. You can use this software for a wide range of analysis types, including stationary, transient, eigenmode/modal, parametric, quasi-static, frequency-response, buckling, and prestressed analyses.

Add-on Products Augment and Supplement Your Structural Analyses

The Structural Mechanics Module provides user interfaces for analyses in 2D, 2D axisymmetry, and 3D coordinate systems for solids, shells (3D), plates (2D), trusses (2D, 3D), membranes (2D axisymmetry, 3D), and beams (2D, 3D). These allow for large deformation analysis with geometrical nonlinearity, mechanical contact, thermal strain, piezoelectric materials, and fluid-structure interaction (FSI). If you are looking to perform nonlinear materials analysis, there are two add-on products available to you – the Nonlinear Structural Materials Module and the Geomechanics Module. For fatigue life evaluation, you can leverage the add-on Fatigue Module, while if you are looking to model flexible and rigid body dynamics, the add-on Multibody Dynamics Module is for you. The Structural Mechanics Module also works in tandem with COMSOL Multiphysics and the other application-specific modules to couple structural analysis with a wide range of multiphysics phenomena, including the interaction of mechanical structures with electromagnetic fields, fluid flow, and chemical reactions.

Fatigue Evaluation

By adding the Fatigue Module to your structural mechanics analyses, you can perform structural fatigue life computations. Both high-cycle and low-cycle fatigue methods, and cumulative damage analysis are available. The Fatigue Module is tightly integrated with the Structural Mechanics Module and you remain in the COMSOL Desktop® environment for the structural mechanics and for fatigue computations. The Fatigue Module can be used together with the Solid Mechanics, Shell, Plate, and Multibody Dynamics interfaces as well as for the physics interfaces that simulate thermal stresses, joule heating together with thermal expansion, and piezoelectric devices.

Beams and Trusses

Beam elements in the Structural Mechanics Module are intended for the analysis of slender structures (beams) that can be fully described by cross section properties, such as areas and moments of inertia. They simulate frame structures, both planar and in 3D, and can be coupled with other element types, such as for analyzing reinforcements of solid and shell structures. The Beam interface includes a library for rectangular, box, circular, pipe, H-profile, U-profile, and T-profile beam sections. Additional features include damping, thermal expansion, and initial stresses and strains. A separate 2D physics interface, called Beam Cross Sections, can be used to evaluate cross section properties for arbitrary 2D cross sections to use as inputs in beam analyses.

The Truss interface can be used to model slender structures that can only sustain axial forces. Trusses allow specification of small strains as well as large deformation strains. Examples of truss structures are truss works with straight edges and cables exposed to gravity forces (sagging cables). Additional features include damping, thermal expansion, and initial stresses and strains.

Thermal Stress

While the Structural Mechanics Module works together with COMSOL Multiphysics, and can be integrated with other add-on modules to model many different multiphysics applications, it does include a number of tailor-made multiphysics interfaces. For instance, the Thermal Stress interface is similar to the Solid Mechanics interface with the addition of a thermal linear elastic material model. It can be used in combination with various Heat Transfer interfaces to couple the temperature field to a structure’s (material) expansion. A special Joule Heating and Thermal Expansion multiphysics interface combines Thermal Stress with Joule Heating and describes the conduction of electric current in a structure, the subsequent electric heating caused by the ohmic losses in the structure, and the thermal stresses induced by the temperature field.

Additional Mechanical Modeling Capabilities in Other Modules

The MEMS Module provides dedicated tools for structural simulations specific to micromechanical systems. It offers physics interfaces for piezoresistivity, electromechanical deflection, thermoelastic vibration, and more advanced modeling tools for analyzing piezoelectric devices. From a mechanical analysis perspective, the Acoustics Module covers structural vibration in combination with acoustic pressure waves and elastic and poroelastic wave propagation. The Subsurface Flow Module enhances the Solid Mechanics interfaces with poroelasticity in combination with porous media flow.

CAD and Optimization

The CAD Import Module provides the ability to import a range of industry-standard CAD formats, including geometry clean-up and repair operations for preparing CAD models for meshing and analysis. The CAD Import Module also provides the well-known Parasolid^® geometry kernel for more advanced solid operations than what is supported with the COMSOL native kernel. For mechanical simulation of electronics structures, the ECAD Import Module offers electronic layout import. When analyzing a mechanical part or assembly, it is vital to keep the CAD-native parametric model so that parameter studies and optimization can be performed without having to reconstruct model parameters. This is made possible by using the LiveLink™ products for CAD that are available for several leading CAD systems: SOLIDWORKS^®, s, Inventor^®, AutoCAD®, PTC^® Creo^® Parametric™, PTC^® Pro/ENGINEER^®, and Solid Edge^®. These products offer simultaneous updates of geometry parameters in the CAD system and COMSOL, and allow for parametric sweeps and optimization over several different modeling parameters. By including the Optimization Module, automated optimization is possible for geometric dimensions, boundary loads, or material properties.

Piezoelectric Devices

The Piezoelectric Devices interface combines COMSOL's Solid Mechanics and Electrostatics modeling capabilities into a fully coupled tool for modeling piezoelectric materials. The piezoelectric coupling can be in stress-charge or strain-charge form with fully coupled frequency-sweep, eigenmode, and transient computations. All solid mechanics and electrostatics functionality is accessible through this physics interface, to model the surrounding linear elastic solids or air domains as well as dielectric layers, for example.

Fluid-Structure Interaction (FSI)

The Fluid-Structure Interaction (FSI) multiphysics interface combines fluid flow with solid mechanics to capture the interaction between the fluid and the solid structure. Solid Mechanics and Laminar Flow interfaces model the solid and the fluid, respectively. The FSI couplings appear on the boundaries between the fluid and the solid, and can include both fluid pressure and viscous forces, as well as momentum transfer from the solid to the fluid – bidirectional FSI. The method used for FSI is known as an arbitrary Lagrangian-Eulerian (ALE).