Mohd Yuhazri Yaakob

The Effects of Triggering Mechanisms on the Energy Absorption Capability of Circular Jute/Epoxy Composite Tubes under Quasi-Static Axial Loading

The usage of composite materials have been improving over the years due to its superior mechanical properties such as high tensile strength, high energy absorption capability, and corrosion resistance. In this present study, the energy absorption capability of circular jute/epoxy composite tubes were tested and evaluated. To induce the progressive crushing of the composite tubes, four different types of triggering mechanisms were used which were the non-trigger, single chamfered trigger, double chamfered trigger and tulip trigger. Quasi-static axial loading test was carried out to understand the deformation patterns and the load-displacement characteristics for each composite tube. Besides that, the influence of energy absorption, crush force efficiency, peak load, mean load and load-displacement history were examined and discussed. The primary results displayed a significant influence on the energy absorption capability provided that stable progressive crushing occurred mostly in the triggered tubes compared to the non-triggered tubes. Overall, the tulip trigger configuration attributed the highest energy absorption.

Physical and Sound Absorption Properties of Spent Tea Leaf Fiber Filled Polyurethane Foam Composite

Spent tea leaves (STL) from tea producing factories can be considered as new resources for sound absorbing polyurethane (PU) matrix composite materials because STL are rich in polyphenols (tannins) which cause high durability, high resistance to fungal and termites, and high resistance to fire. The research aims to study the physical characteristics of STL and the effect of dispersion morphology of STL on the sound absorption properties of polyurethane foam composites by varying filler loading. Three grades of STL fibers either as received or granulated are used in this study, namely BM-FAE and SWBHE derived from the stalk while FIBER-FAE derived from the leaves of the tea plant. The PU/STL composites are fabricated through open molding method with a fiber loading of 16 wt. %. The fabricated composites are then subjected to physical and sound absorption testing as well as microscopic observations to analyze the distribution of filler in composite. The study shows that as-received FIBER-FAE spent tea leaves provide the best sound absorption coefficient and for composites using granulated fibers from any grade have lower sound absorption coefficient. These results show that a novel kind of sound absorption materials with the recycling of waste materials can be obtained for the solution of noise and environmental pollution.

Study on the Use of Micro-Perforated Panel to Improve Acoustic Performance in Mosque

Most activities in mosque such as Friday prayer and the sermon by an Imam require clarity of speech. Unfortunately, this speech intelligibility performance is often poor due to initial design of a mosque. This paper presents assessment of the indoor acoustics of a mosque. Acoustical properties such as reverberation time, clarity and early decay time are obtained from simulation data using CATT indoor acoustic software. The study started with an empty mosque with no acoustic treatment. Acoustic green absorbers using micro-perforated panel (MPP) are then introduced to improve the acoustic performance. The application of MPP is still rare for mosque and is expected to replace the typical porous absorber. The effect of the panel size, location and frequency range of sound absorption are simulated and the results are discussed.

Real of Simply Assembly Line Balancing using Fact-Model

This study is to examine the productivity of the designated production line related to the cycle time, takt time, non-value added activities, and product quantities in which the processing time and the number of operators are having the correlation with assembly line balancing. By using a developed simulation tool, called as Fact-Model; which having facility menus such as the graph of critical path network, working time, and production table, enable users to analyze the line assembly related to idle time and bottleneck as well as to address the unbalancing causes. Fact-Model is also facilitate users to apply their owned pictures (which is taken related to process) in order to depict and map the real characteristic of production flows. Based on the simulation carried out, where the reallocation activities in Main-Board production line are undertaken through the production process and operators reassigned, it shows that productivity is optimum.

Modeling of a Jig Sampling and its Application in Disc Cutter Tools

The operations of preparing the deform sample and round bar mainly consist of the calculation of the bars unit weight. The Sampling process is conducted through the two cutting flows such as in line production and disc. The problems are then occurred in the second flow (in disc) in performing the cutting process on a certain length. Modeling of the jig sampling is used to solve this problem and also fully discussed throughout this paper.

Effects of triggering mechanisms on the crashworthiness characteristics of square woven jute/epoxy composite tubes

The usage of composite materials has been growing widely over the years due to their excellent characteristics such as lightweight, high-energy absorption capability and corrosion resistance. In this study, the crashworthiness characteristics of square woven jute/epoxy composite tubes with different configuration of triggering mechanisms were tested and evaluated when subjected to quasi-static axial loading. The deformation morphology of each composite tube was captured by using high-resolution photography. The composite tubes were fabricated by using the combination of hand layup and compression bladder moulding techniques in which total of three layers of woven bi-directional natural jute fabric (plain weave mat) were used, each with wall thickness and length of 3 mm and 100 mm, respectively. To induce the progressive crushing of composite tubes, four different types of triggering mechanisms were used: the non-trigger, single chamfered trigger, double chamfered trigger and tulip trigger. The influence of energy absorption, crush force efficiency, peak load, mean load and load–displacement history was examined and discussed. From this study, most of the composite tubes failed in progressive manner rather than catastrophic failure. Overall, the tulip trigger configuration is considered the optimal design for crashworthy structure applications.

Hardness of Laminated Composite for Different Angle Cured Positions under Influence of Gravity Effects

Utilization of high tech engineering materials such as composites has been extensively applied in the industries of civil, mechanical and aerospace due to their favourable characteristic such as high stiffness to weight ratio, improve corrosion and environmental resistance and potential reduction of processing. This research is carried out to study the feasibility of laminated composite after cured at different angle due to gravity effects to enhance the curing space required. Vertically cured laminate having similar or improved properties with common horizontally cured laminate to save much space bringing huge advantage especially to the developing Small and Medium Industries / Entrepreneurs (SMI/E). The horizontal cured laminate composite no doubt will fill up the spaces which SMI/E lacks of. Polyester and E-type fiber glass were the main raw materials used in the research via vacuum bagging technique to drain out the excess resin applied as well as minimize the void or air in the laminated composite. The laminated composite fabricated is cured at different curing angle positions in room temperature for 24 hours under the gravity effects. Five samples were prepared according to the ASTM standard to undergo hardness test. From the testing, SN6 which cured at 75˚ had the closest hardness to the horizontal cured control sample.

Gravity Effects on the Density of Laminated Composite due to the Differences in Angle Cured

This research is carried out to study the feasibility of the gravity effects on curing position of the laminated composite structures to enhance the curing space needed. Vertical cured laminate having almost similar properties with common horizontal cured laminate able to save much space in composite industry especially for developing Small and Medium Industry (SMI). Horizontal cured laminates filled up spaces in which SMI lack of. Polyesters and E-glass fibers were used as the raw material in this research. Vacuum bagging technique was used to suck out the excess resin during lay-up to avoid any voids and air inside laminate and cured at different angle position in room temperature for 24 hours. Seven samples of laminated composite were fabricated and cut into specific dimension in accordance to ASTM standard. The aim of the research was to investigate the density property of the thermosetting laminated composite by curing the laminate at different angle using vacuum bagging technique. From the testing, SN6 had the same density value with control sample, SN1 that had value of 1.46 g/cm3.

Water Absorption and Thickness Swelling of Laminated Composite after Cured at Different Angle

Moisture absorption is a very important factor in polymers and composite materials used for hull manufacture and stability in marine environment. High water absorption of the material will affects the mechanical properties and stability in composite. This research is carried out to study the feasibility of the gravity effects on curing position of the laminated composite structures to enhance the curing space needed. Vertical cured laminate having almost similar properties with common horizontal cured laminate able to save much space in composite industry. Horizontal cured laminates filled up spaces in which SMI lack of. Polyesters and E-glass fibers were used as the raw material in this research. Vacuum bagging technique was used to suck out the excess resin during lay-up to avoid any voids and air inside laminate and cured at different angle position in room temperature for 24 hours. Seven samples of laminated composite were fabricated and cut into specific dimension in accordance to ASTM standard. This paper will discuss about the investigation on the water absorption and thickness swelling of the thermosetting laminated composite by curing the laminate at different angle using vacuum bagging technique. From the testing, SN6 and SN7 shows to have good water resistant in physical properties.

Tensile Properties of Angle Cured Laminated Composites Structures under Gravity Effects

As the usage of composites materials are significant in the industries of automobiles, shipping and constructions due to their non-corrosive and high strength to weight ratio. Anyway, the production of composites needed to be increased to meet the demand. At this stage, problem faced by Small and Medium Industries / Entrepreneurs (SMI/E) is the confined and limited space available that restricts the optimum productivity. They commonly cure the composites horizontally that requires ample space and unable to afford for high-end equipment such as mechanical oven and autoclave in the production as a result of high capital cost.This research is carried out to study the feasibility of the gravity effects on curing position of the laminated composite structures to enhance the curing space needed. The aim of the research was to investigate the tensile properties of the thermosetting laminated composite by curing the laminate at different angle using vacuum bagging technique. From the testing, SN 5 which denominated to be 60 ̊ found to have the best tensile properties in term of maximum force exerted and Youngs modulus.