Structural Mechanics Module
User Stories
Example Models
 | A fuel cell stack operates at temperatures just below 100 °C, which means that it has to be heated at start-up. The fuel cell stack consists of unit cell of anode, membrane, and cathode connected in series through bipolar plates.... |
 | This example studies the deflection of a cantilever beam undergoing very large deflections. In addition, a linearized buckling analysis of the structure is also performed.
The model comes from Section 5.2 of NAFEMS Background to Finite... |
 | The model performs a static analysis on a piezoelectric actuator based on the movement of a cantilever beam, using the Piezoelectric Devices predefined multiphysics interface. Inspired by work done by V. Piefort and A. Benjeddou, it... |
 | The conditions within gas turbines are extreme. The pressure can be as high as 40 bar, and the temperature more than 1000 K. Any new component must therefore be carefully designed to be able to withstand thermal stresses, vibrations and... |
 | A tube connection consisting of a flange with four pre-stressed bolts is subjected to tensile forces.
Two contact regions are modeled: one between the bottom surface of the flange and the top surface of an additional fixed solid, and... |
 | The rotor in an electric motor is analyzed. In the design of a motor it is important that no eigenfrequencies for the rotor lie within the operating interval of the revolution speed (in revolutions / second) for the motor. If the... |
 | The vibration modes of a thin or thick circular disc are well known, and it is possible to compute the corresponding eigenfrequencies to arbitrary precision from a series solution. The same is true for the acoustic modes of an air-filled... |
 | Planar photonic waveguides in silica (SiO2) have great potential for use in wavelength routing applications. The major problem with this type of waveguide is birefringence. Anisotropic refractive indices result in fundamental mode... |
 | The combustion process at steady-state produces cyclic pressure loads and high constant temperatures. These load conditions yield a piston failure due to fatigue cracking, so-called high cycle fatigue cracks.
In this model, a diesel... |
 | Viscoelastic materials have a time-dependent response, even if the loading is constant. Many polymers and biological tissues exhibit such a behavior. Linear viscoelasticity is a commonly used approximation, where the stress depends... |
 | In this model, you build and solve a 2D beam model using the 2D Structural Mechanics Beam interface. This model describes the eigenfrequency analysis of a simple geometry. A point mass and point mass moment of inertia are used in the... |
 | In this example you will build and solve a 3D beam model using the 3D Beam interface.
This model shows how a thermally induced deformation of a beam is modeled. Temperature differences are applied across the top and bottom surfaces as... |
 | A benchmark model where a thick plate exposed to pressure on the top surface is analyzed.
The solution is compared with a NAFEMS benchmark solution. |
 | This model describes a static stress analysis to obtain the stress distribution in the vicinity of a small hole in an infinite plate. The model is a classic benchmark and is described in Mechanics of Material, by D. Roylance. The stress... |
 | This model calculates the eigenfrequencies and mode shapes of an unconstrained cylinder in axisymmetry.
The model is taken from NAFEMS Free Vibration
Benchmarks. The eigenfrequencies are compared with the values given in the... |
 | A long elastic cylinder resting on a flat rigid foundation is analyzed. The cylinder is subjected to a uniform load along its top. The contact pressure distribution is compared with the analytical solution |
 | The thermal stress in a layered plate is studied in this example. A plate consisting of two layers, a coating and a substrate layer is stress and strain free at 800 degrees C. The temperature of the plate is reduced to 150 degrees C and... |
 | A thick wall cylinder is exposed to both internal and external pressure and thermal load.
The model is both plane and axisymmetric. The results are compared to the analytic solution.
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 | In this model, a thick square plate is excited by a harmonic uniform pressure. A frequency sweep is performed to find the frequency with maximum displacement. The solution is compared with a NAFEMS benchmark |
 | One way to fasten a gear to a shaft is by thermal interference. In preparation of the assembly, the shaft diameter is oversized and the gear thermally expanded in a heat-treating oven. At an appropriate expansion state, the gear is... |
 | A contactor wedge is subject to a gravity load and is forced to slide due to a boundary load over a rigid target wedge surface, both infinitely wide. Horizontal linear springs are also connected between the left vertical boundary and the... |
 | Liquid or gas acoustics coupled to structural objects such as membranes, plates or solids are important applications in many engineering fields.
This model is a general demonstration of an acoustic fluid phenomenon in 3D that is... |
 | Small heating circuits find use in many applications. For example, in manufacturing processes they heat up reactive fluids. The device used consists of an electrically resistive layer deposited on a glass plate. The layer causes Joule... |
 | The drive for miniaturizing electronic devices has resulted in today’s extensive use of surface-mount electronic components. An important aspect in electronics design and the choice of materials is a product’s durability and lifetime.... |
 | In this example a thin curved membrane is built and solved using the Shell interface. This model is a widely used benchmark model denoted the Scordelis-Lo roof.
The computed maximum z-deformation is compared with the value given in... |
 | This model refers to a portion of the vascular system of a young child - the upper part of the aorta artery. The blood vessels are embedded in a biological tissue (the cardiac muscle) and, during the flow of blood, pressure is applied to... |
 | Microwave filters are used to eliminate unwanted frequency components in the output from microwave transmitters. They are typically inserted between a power amplifier and an antenna. The amplifiers are nonlinear and produce harmonics that... |
 | A microrobot's leg, which structurally moves due to the rapid application of heat, is modeled in this example. Heat is generated by an electric current and propagates by conduction through the leg and, due to thermal expansion and... |
 | The most common reason that people have hip-replacement surgery is due to the wearing down of the hip joint that results from osteoarthritis. Other conditions, such as rheumatoid arthritis (a chronic inflammatory disease that causes joint... |
 | This model is compared to a NAFEMS benchmark for composite material modeling, No R0031/2. The geometry is a long, thick, and hollow cylinder consisting of two layers, where an internal pressure is applied. The inner layer is made from an... |
 | In a peristaltic pump, rotating rollers squeeze a flexible tube. As the rollers move along the tube, the fluid in the tube follows the motion. The main advantage of the peristaltic pump is that no seals, valves or other internal parts... |
 | In this model, fluid is flowing through a channel containing a flexible obstacle. Due to the viscous and pressure forces asserted by the fluid, the obstacle bends. With the obstacle undergoing a large deformation, the fluid flow domain... |
 | This model deals with the stability of a plate with an edge crack that is subjected to a tensile load. To analyze the stability of exciting cracks, fracture mechanics can be utilized.
A commonly used parameter in fracture mechanics,... |
 | This model analyzes the thermal expansion in a MEMS device, such as a microgyroscope, where thermal expansion should be minimized. The device is made from the copper-beryllium alloy UNS C17500 and uses temperature-dependent material... |
 | Consider an infinitely long steel cylinder resting on a flat aluminum foundation, where both structures are elastic. The cylinder is subjected to a point load along its top. The objective of this study is to find the contact pressure... |
 | A piezoelectric transducer can be used either to transform an electric current to an acoustic pressure field or, the opposite, to produce an electric current from an acoustic field. These devices are generally useful for applications that... |
 | This is an overview presentation on the elastic waves and piezoelectric modeling features of COMSOL Multiphysics. The focus here is on piezo-features and especially COMSOL's strength in that you are allowed to mix dielectric, elastic,... |
 | A frame with a central cutout is subjected to a random load consisting of 1000 load events. The external load, recorded using three strain gauges, is simulated using superposition of three unit loads. The stress state around the cutout is... |
 | When a structure is subjected to high frequency vibrations, a significant amount of heat can be generated due to mechanical (viscoelastic) losses in the material. A second mechanism contributing to the slow temperature rise in a vibrating... |
 | This model shows how to implement a stress dependent elasticity problem. The material Young's modulus is changing based on the stress value. |
 | This presentation gives an overview of the Structural Mechanics Module and other modules of interest for structural analysis. It demonstrates which solid mechanics problems can be simulated and which study types can be solved. Advanced... |
 | In massive forming processes like rolling or extrusion, metal alloys are deformed in a hot solid state with material flowing under ideally plastic conditions. Such processes can be simulated effectively using computational fluid dynamics,... |
 | Damping elements involving layers of viscoelastic materials are often used for reduction of seismic and wind induced vibrations in buildings and other tall structures. The common feature is that the frequency of the forced vibrations is... |
 | This model studies the temperature effects on the viscoelastic stress relaxation in a long thick-walled cylinder. In particular, decay of the stresses under the influence of the temperature field during a period of two hours is studied. A... |
 | This example shows how to parameterize a CAD model by deforming the corresponding finite element mesh.
The method enables geometry parameterization of non-parameterized CAD models such as:
- models created by the built-in COMSOL... |
 | Magnetostrictive transduction is used in sonars, acoustic devices, active vibration and position control and fuel injection systems. The transducer has a steel housing enclosing a drive coil. A magnetostrictive material is placed in the... |
 | This tutorial model demonstrates the use of dynamic cyclic symmetry with postprocessing on the full geometry. A 3D impeller with eight identical blades can be divided into eight sectors of symmetry. The model computes the fundamental... |
 | This tutorial model of a two-hot-arm thermal actuator couples three different physics phenomena: electric current conduction, heat conduction with heat generation, and structural stresses and strains due to thermal expansion. In this... |
 | This model is inspired by a classic bridge type called a Pratt truss bridge. You can identify a Pratt truss by its diagonal members, which (except for the very end ones) all slant down and in toward the center of the span. All the... |
 | In stress analysis, it is common that the regions with high stresses are small when compared to the whole structure. Sometimes it is not feasible to have a mesh that at the same time captures the global behavior and resolves the stress... |
 | In this model, you build and solve a simple 3D beam model using the 3D Beam interface. This model calculates the deformation, section forces, and stresses in a cantilever beam, and compares the results with analytical solutions. The first... |
 | A plate modeled using the Plane Stress interface is loaded above the elastic limit. The material is elastoplastic with isotropic hardening. The plot shows the plastic zone. |
 | Trusses are elements which can only sustain axial forces. You can use trusses to model truss works where the edges are straight as well structures like sagging cables.
In the following example you first build and solve a simple 2D... |
 | This example studies the deformation of a hemispherical shell, where the loads cause significant geometric nonlinearity. The maximum deflections are more than two magnitudes larger than the thickness of the shell. The problem is a... |
 | This model studies the natural frequencies of a pre-tensioned string using the 2D Truss interface. This is an example of “stress stiffening”; in fact the transverse stiffness of truss elements is directly proportional to the tensile... |
 | This is a benchmark model involving stick-slip friction of a ring rolling inside another ring. The displacement of the inner ring is computed and compared to the analytical result.
This model also shows how to tackle friction dominated... |
 | High rotational speed in rotating machineries can result in centrifugal forces of considerable magnitude. The forces induced by the rotation give rise to two counteracting effects: stress-stiffening and spin-softening (or centrifugal... |
 | A classical flow pattern is the von Kármán vortex street that can form as fluid flows past an object. These vortices may induce vibrations in the object. This problem involves a fluid-structure interaction where the large deformation... |
 | The model studied is a benchmark for a hinged cylindrical panel subjected to a point load at its center. A linear buckling analysis predicts the critical buckling load. Such an analysis will however not give any information about what... |
 | These models are used for an introduction to structural mechanics modeling using the structural mechanics module.
The following features are introduced:
- The Fundamentals: A Static Linear Analysis
- Parametric study
- Including... |
 | In many structural dynamics applications, some components are stiff compared to the supporting structure. Such a stiff part will only contribute to the dynamic properties of the structure through its mass and moment of inertia. It is then... |
 | In mechanical assemblies, parts are sometimes connected so that they are free to move relative to each other in one or more degrees of freedom. Examples of such connections are ball joints, hinges, and different types of bearings. If the... |
 | Trusses are commonly used to create light structures that can support heavy loads. When designing such a structure, it is important to ensure its safety. For a tower made of bars, buckling can cause the structure to collapse. This model... |
 | Several numerical algorithms exist to tackle structural contact problems. The one used in COMSOL Multiphysics is based on the so-called Augmented-Lagrangian method.
An alternative approach presented in this example model is called the... |
 | The natural frequencies of a prestressed circular membrane are computed and compared with analytical solutions. Two method are used: In the first study the prestress is given explicitly, while in the second study an external load provides... |
 | Transient analysis of the wave propagation in rock mass caused by a short duration load on the surface. Such loads are typical during tunnel constructions and other excavations using blasting.
The model shows the use of the... |
 | This is a benchmark model for a plane stress problem. The accuracy of the computed stress concentration is evaluated, and a mesh convergence study is performed for different element types.
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 | This model describes the pressure wave propagation in a muffler for an internal combustion engine. The purpose of the model is to show how to analyze both inductive and resistive damping in pressure acoustics as well as coupling the... |
Papers & Presentations
