Computation of Eigenvalue-Eigenvector and Harmonic Motion Solution for Laminated Rubber-Metal Spring

This paper presents the modeling of multi-degree-of-freedom on laminated rubber-metal spring in axial direction displacement. Two methods are used which are firstly the eigenvalues and eigenvectors solution and secondly called harmonic motion solution. In eigenvalues and eigenvectors approach, equation of motion of laminated rubber-metal spring is developed using spring-mass system. Then, the equation was rewritten again in matrix and harmonic motion in order to reduce the difficulty and become realistic to be solved using characteristic equation. On the other hand, harmonic motion approach is started from governing equation in term of mode shape. By using this concept, two important equations are finally derived which are displacement and velocity. Using these two methods, finally the maximum displacements of laminated rubber-metal spring are plotted as well as in frequency domain axis. Two types of analysis are considered in this study which are undamped and damped system. Based on the results obtained, the maximum displacement occurred at undamped system. By increasing the number of degree-of-freedom, the displacement is slowly reduced

Microscopic Study on the Natural Rubber with Different Carbon Loadings under Compression: SMR CV-60 AND ENR 25

This study presents the microscopic investigation related to the effects of compression on the local natural rubber (NR): the standard Malaysian rubber constant viscosity-60 (SMR CV-60) and the epoxidized natural rubber 25% mole (ENR 25) at four different carbon loadings (0, 20, 40 and 60 pphr). The surface morphology of both NR was studied by using scanning electron microscope (SEM). The results showed that a packed and folded surface was observed on the SMR CV-60 while a crumpled surface was observed on the ENR 25. However, the packed and folded and the crumpled surfaces were decreased as the carbon loading in NR compound was increased. It also showed that the applied compression does not exhibit any significant effects on both compound since the damages only found on the outer layer of rubber surface. The experimental value shows that the NR deflection in response to the compression is reduced as the carbon loading increase. The SMRCV60/0 and ENR25/0 have recorded the highest deflection due to the compression. Meanwhile, the SMRCV60/60 and the ENR25/60 has recorded the lowest deflection under the compression. Through this study, it is found that the compression force does not contribute to the NR compound failure

Numerical Simulations of Shear Driven Square and Triangular Cavity by Using Lattice Boltzmann Scheme

In this paper, fluid flow patterns of steady incompressible flow inside shear driven cavity are studied. The numerical simulations are conducted by using lattice Boltzmann method (LBM) for different Reynolds numbers. In order to simulate the flow, derivation of macroscopic hydrodynamics equations from the continuous Boltzmann equation need to be performed. Then, the numerical results of shear-driven flow inside square and triangular cavity are compared with results found in literature review. Present study found that flow patterns are affected by the geometry of the cavity and the Reynolds numbers used