Mohd Azli Salim

TRANSMISSIBILITY OF A LAMINATED RUBBER-METAL SPRING A PRELIMINARY STUDY

This paper discusses the isolation performance of a laminated rubber-metal spring. A multi-degree-of-freedom-system model using mass-damper-spring components is developed to calculate its transmissibility due to only axial vibration in the spring. The results show the embedded layers of metal plate can improve the transmissibility at high frequency.

Analysis of Axial Vibration in the Laminated Rubber-Metal Spring

The laminated rubber-metal spring is well known in application as the vibration isolator for earthquake protection. The spring is therefore designed to be able to sustain the vibration waves from horizontal direction. This paper discusses the possibility of the laminated spring to be employed for other applications where the excitation mainly comes from axial direction, such as to isolate vibration transmission from heavy engine. The model is first developed for a simple finite rod to simulate the effect of internal resonances at high frequency when the wavelength is much smaller than the length of the rod. The effect of metal plates inserted in the rubber is then modelled using the lumped parameter system. The results are presented in terms of the vibration transmissibility.

Analysis Of Parameters Assessment On Laminated Rubber-Metal Spring For Structural Vibration

This paper presents the analysis of parameter assessment on laminated rubber-metal spring (LR-MS) for vibrating structure. Three parameters were selected for the assessment which are mass, Youngs modulus and radius. Natural rubber materials has been used to develop the LR-MS model. Three analyses were later conducted based on the selected parameters to the LR-MS performance which are natural frequency, location of the internal resonance frequency and transmissibility of internal resonance. Results of the analysis performed were plotted in frequency domain function graph. Transmissibility of laminated rubber-metal spring (LR-MS) is changed by changing the value of the parameter. This occurrence was referred to the theory from open literature then final conclusion has been make which are these parameters have a potential to give an effects and trends for LR-MS transmissibility.

Dynamic performances analysis of a real vehicle driving

Vehicle dynamic is the effects of movement of a vehicle generated from the acceleration, braking, ride and handling activities. The dynamic behaviours are determined by the forces from tire, gravity and aerodynamic which acting on the vehicle. This paper emphasizes the analysis of vehicle dynamic performance of a real vehicle. Real driving experiment on the vehicle is conducted to determine the effect of vehicle based on roll, pitch, and yaw, longitudinal, lateral and vertical acceleration. The experiment is done using the accelerometer to record the reading of the vehicle dynamic performance when the vehicle is driven on the road. The experiment starts with weighing a car model to get the center of gravity (COG) to place the accelerometer sensor for data acquisition (DAQ). The COG of the vehicle is determined by using the weight of the vehicle. A rural route is set to launch the experiment and the road conditions are determined for the test. The dynamic performance of the vehicle are depends on the road conditions and driving maneuver. The stability of a vehicle can be controlled by the dynamic performance analysis.

Modeling of Mullins Effect on Laminated Rubber-Metal Spring

This paper presents the Mullins effect on the laminated rubber-metal spring analytically modeled using lumped parameter system. The general form of the equation is developed to represent the multi-degree-of-freedom system for layer of embedded metal plates. The Mullins effect can be observed when a compression load is applied to the spring. It is shown that by increasing the embedded metal plate, the Mullins effect inside the rubber is reduced due to the improved stiffness in vertical direction.

Linear and Angular Displacement Relationship of Natural Rubber Engine Isolator

Linear and angular displacement is an important criteria for incompressible materials. Natural rubber is a one of the incompressible material because it has a potential to make uniform displacement when apply the quantum of force. This paper represents the linear and angular displacement of natural rubber engine isolator, respectively. The identity formulation is developed and trivial solution is faced. To doing so, the identity formulation is derived and finally the equation of relationship between linear and angular displacement is derived. Finally, the result has shown the transformation of these two displacements with quantum of frequency.

Dynamic Analysis on Noise and Vibration Study of Flexible Wiper Blade System

Chatter is one of the unwanted noise and vibration phenomenon which are generated during the wiper operation. It is a low frequency and self-excited vibration that is often generated before and after the wiper reverses its direction. This leads to a poor visibility and annoying sound to the driver and passengers. Therefore, this paper is aimed to propose a technique that can be apply to tackle this problem. Hence, an existing two-dimensional mathematical model of a wiper system available in the open literature is adopted. Firstly, the baseline model is simulated in order to observe its vibration response. Then, an input shaping control scheme is introduced into the baseline model. It is found that the input shaping control scheme can reduce the vibration level approximately by 30 percents from the baseline model.

Recent Advances in Polyethylene-Based Biocomposites

Abstract Polyethylene (PE), part of the polyolefins group, is one of the major sources of commodity plastics used as the matrix in the development of biocomposite materials. PE-based biocomposites have been extensively used in both for nonstructural and structural applications, due to the low cost, recyclability, and processing advantages as compared to synthetic based composites. In this chapter, the overview on the application of PE-based biocomposites is explained which includes its role to the biocomposite formulation, various processing methods involved, and the characterization techniques applied to determine the properties of the final composites. In addition, this chapter also describes examples on the application of PE-based biocomposites in several fields such as such as structural, packaging, coating, biomedical, and medical.

Vibration absorber modeling for handheld machine tool

Handheld machine tools produce continuous vibration to the users during operation. This vibration causes harmful effects to the health of users for repeated operations in a long period of time. In this paper, a dynamic vibration absorber (DVA) is designed and modeled to reduce the vibration generated by the handheld machine tool. Several designs and models of vibration absorbers with various stiffness properties are simulated, tested and optimized in order to diminish the vibration. Ordinary differential equation is used to derive and formulate the vibration phenomena in the machine tool with and without the DVA. The final transfer function of the DVA is later analyzed using commercial available mathematical software. The DVA with optimum properties of mass and stiffness is developed and applied on the actual handheld machine tool. The performance of the DVA is experimentally tested and validated by the final result of vibration reduction.

Challenges and Developments of Rubber Materials as Vibration Isolator

Rubber materials have been well known as a vibration isolator to dissipate vibration energy. Most of existing works on the vibration isolator especially the mathematical models only consider the performance of the vibration isolator due to the static force. This study is focused on the antivibration isolator due to the effects of rubber materials in a massless isolator. It also covers the fundamentals of control theory, recent developments in vibration isolators, and challenges of rubber materials as a vibration isolator. At the end of the study, it has been shown that, by increasing the number of degrees-of-freedom in massless isolator, the performance of the vibration isolator can be improved.