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Date of Award


Document Type

Campus Access Master's Report

Degree Name

Master of Science in Mechanical Engineering (MS)

Administrative Home Department

Department of Mechanical Engineering-Engineering Mechanics

Advisor 1

Gregory M. Odegard

Committee Member 1

Jeremy J. Worm

Committee Member 2

Scott W. Wagner


REL Inc. has designed a conformable CNG tank which is different from the ordinary cylindrical shape of the CNG tank. This newly designed tank is rectangular in shape and can fit under the body of the Truck. All the ordinary cylindrical shaped CNG tanks consume a lot of cargo space. With this newly designed CNG tank, the consumer does not have to compromise the cargo space. REL Inc. has partnered with Michigan Tech to study various aspects of the tank using FEA such as topological optimization, structural analysis and meet NGV2 (Natural Gas Vehicle) safety standards.

Physical drop tests have shown satisfactory results with NGV2 drop test criteria. These tests simulated in HyperMesh/RADIOSS by Sumit Bongir and in Abaqus by Paul Roehm have shown little discrepancies in results compared with physical test results.

This report discusses the same experimental drop tests simulated using ANSYS and check for how good ANSYS is in performing such tests, whether ANSYS is a reliable tool to perform such explicit dynamics analysis. This report covers how to use ANSYS to perform explicit dynamics analysis for such tests. It describes various parameters set and the material model used for this test.

One of the findings from this study was about the meshing quality of the ANSYS, that the quality of mesh generated by ANSYS is not good. Also, there are not many tools available to edit these element quality to pass the mesh criteria. Hence, HyperMesh was selected at a later stage to mesh the tank and then use ANSYS as a solver to simulate the test using these already meshed models.

This report concludes that the results obtained by ANSYS are not analogous with the physical test results and we need to work to find out the correct material properties of tank as well as concrete.