Model Gallery
Spinning Gear
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 removed from the oven, slid onto the shaft, and allowed to cool. As the gear temperature drops, the gear shrinks and comes into contact with the shaft before it ...
3D Fluid-Structure Interaction Simulation of an Obstacle in a Fluid Channel
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 also changes considerably. COMSOL Multiphysics takes these changes into account by computing the flow field on a moving mesh attached to the obstacle. In this ...
Parameterized I-Beam
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 CAD tools - imported neutral CAD files such as .igs or .step - imported .x_t, .sat, or other vendor-specific formats - imported finite element mesh files The module ...
Submodel in a Wheel Rim
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 concentrations with high accuracy. This is especially true in nonlinear or dynamic problems. You can cope with this type of problems with a technique known as ...
Modeling Rigid Bodies
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 possible to reduce the model size significantly by treating it as a rigid body. In this example the eigenfrequency of an assembly is computed where one of the ...
Absorptive Muffler with Shells
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 fluid to the surrounding elastic shell structure of the muffler. Finally, the eigenmodes of a pure structural problem is analyzed and the modes compared to peaks in ...
Critical Frequencies for a Rotor
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 eigenfrequencies of the rotor lie in this interval then this shortens the engines lifetime, and can sometimes even lead to dysfunction and breakdown. This 3d model of ...
Diesel Engine Piston
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 engine piston is studied under a continuous engine speed and load.
Viscoelastic Material Model
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 linearly on the strain and its time derivatives. For many materials, the viscoelastic properties have a strong dependence on the temperature. A common assumption is ...
Kirsch Infinite Plate Problem
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 level is then compared with the theoretical values.
