3RD INTERNATIONAL CONGRESS ON TECHNOLOGY - ENGINEERING & SCIENCE - Kuala Lumpur - Malaysia (2017-02-09)

Structural Design Analysis Of A Prototype Vehicle

Designing a prototype three wheeler vehicle structure used for endurance competition purpose required a study on material selection, type and size of beam, load cases and the structural design itself. As a major component of vehicle, a satisfactory structure is designed to overcome deformation and bending stresses when subjected to loads. In addition, a lightweight structure is considered to ensure the performance of overall vehicle without neglecting the strength and stiffness condition of the structure. Design phase starts by selecting a few conceptual structure designs. For the analysis, the beam stiffness method will be used to determine the nodal displacement of the structure. In the stiffness method analysis, a single aluminium beam type and size is selected which the standard moment of inertia and the modulus of elasticity of the beam will be used throughout the analysis for all conceptual structure designs. The analysis begins by defining the element stiffness matrix for each elements based on 2-D modelling of the design. All element stiffness matrixes are then assembled to get the global stiffness matrix form. The structure is modelled using 4 elements with node 1, 2, 3, 4 and 5. Using the standard load case, the work equivalent for each element is computed based on its individual loading W and length L in order to get the global work equivalent load for whole structure. From the global work equivalent load, it will be converted into global equilibrium equation in order to obtain the slope and displacement value for each nodes using Gaussian elimination method. The best structure design then will be chose based on its less deformation value and bending stress condition. From the best structure design, design optimization is carried out in order to find the most suitable beam type and size. The sizing range for beam diameter or width is set between 19.05 mm (0.75 inch) to 38.10 mm (1.5 inch). The beam type is extended to round and rectangular beam in order to evaluate any possibility to get better deformation condition on the structure. Besides, the optimization process is extended by considering the structure’s wheel base length. The best wheel base length is also measured base on the displacement and nodal stress value of the structure. At this stage, the final length of structure can be defined including the best type and size of the beam that will be used. These parameters are then used to generate the CAD drawing using Catia V5R16 software. Generative Part Structural analysis is carried out to solve a static problem which the part is fixed at one or more points and the load is applied to the body. These findings will be used as a comparison with the displacement and stress value of the structure obtained from the manual stiffness method analysis. As a conclusion, the analysis findings either by the theoretical calculation using beam stiffness methods or computational method via generative structural analysis produced an acceptable limit of the displacement value and stresses required for the design.
Keywords: Beam Stiffness Method, Bending Stress, Displacement, Finite Element Methods, Structure
Dzulkarnain bin Mohd Ali, Norshah Afizi bin Shuaib, Nurhuda binti Ismail, Siti Sarah binti Raseli, Nur Intan Syafinaz binti Ahmad