Case Studies > Mechanical
Case List
Case 1: MEMS  Triplebeam Resonator
Case 2: IBeam under Pressure
Case 3: BoxBeam under Contact
Case 4: Mechanism of Piston
Case 5  Shell Vessel under Inner Pressure
Case 2: IBeam under Pressure
Case 3: BoxBeam under Contact
Case 4: Mechanism of Piston
Case 5  Shell Vessel under Inner Pressure
Case 1: MEMS  Triplebeam Resonator
The Eigenfrequency simulation of a resonator with three beams is conducted. Two surfaces are applied with "fixed constraint". The three beam split their eigenfrequency into 6 modes.
Fig. 13 3 outofplane modes

Fig. 14 3 inplane modes

Case 2: IBeam under Pressure
A Ibeam with the plasticity material model is analyzed. Because of symmetric geometry, the model is partitioned and a half is deleted. In the symmetric model, the thick wall can be considered as a rigid domain, so a further simplification can be executed by removing the thick wall domain and applying a fixed boundary condition. To use "Mirror 3D" data set, the vonMises stress distribution on the whole Ibeam can be obtained.
Case 3: BoxBeam under Contact
A boxbeam with the plasticity material model is analyzed. Two cylinders under the beam are fixed, and the third cylinder moves downward to compress the box. Because of symmetric geometry, a quarter of the whole model is simulated. To define finer mesh in contact areas and well predict contact interaction, the one quarter of the boxbeam is partitioned. Two defined "Mirror 3D" data sets helps mirror the simulated vonMises stress distribution on the whole model.
Case 4: Mechanism of Piston
This model is to simulate the rotation process of a piston and to verify the mechanism design using COMSOL software. The figure below on the left shows the schematic of the model including three major parts, which are connected to each other with joints. Since here joints are not our design interest, 5 Rigid connectors are used to represent joints, simplify the model and transfer the necessary constraints. The video on the right shows the simulated results. It can be seen that rigid connectors can perform quite well to represent joints in mechanism simulation.
Fig. 43 Simulated results
Case 5  Shell Vessel under Inner Pressure
Shell element type is crucial for thinstructure models. It would significantly reduce the total DOF of the thinstructure models while still guarantee the accuracy if compared with brick or tetrahedral element type. COMSOL software has a powerful Model Builder to build models independent of CAD software. It also provides an easy way to define the simulation using shell element.