Now showing 1 - 10 of 48
  • Publication
    Fatigue life investigation of UIC 54 rail profile for high speed rail
    ( 2017-10-29)
    Gurubaran Panerselvan
    ;
    ;
    Nur Fareisha M. A.
    ;
    ;
    Haftirman I.
    ;
    This study is to investigate the fatigue life of high speed rail in Malaysia. This paper describes about the experimental and simulation analysis investigation on fatigue life of rail profile UIC 54 using bulk specimen according to ASTM E 466-15 standard. The Fatigue life testing was performed in the fatigue testing machine (Instron 8800) 100 kN. Meanwhile, the fatigue life analysis was performed in ANSYS Workbench 14.5. Furthermore, the stress levels for experimental testing were applied as 16.7%, 25%, 35%, 50%, 58.3%, 66.77% and 75% with machine frequency of 20 Hz. Apart from that, the total fatigue life cycles for rail profile UIC 54 were acquired from both experimental and simulation. The fatigue life S-N curves were plotted and validated with the results of the simulation analysis with experimental results.
  • Publication
    Finite element modelling of thin intermetallic compound layer fractures
    A thin intermetallic compound (IMC) of solder ball joint induces strong stress concentration between the pad and solder where a crack propagated near the IMC layer. The fracture mechanism of the IMC layer is complex due to the effect of IMC thickness, crack length, solder thickness and Young’s Modulus. At present, there is still an undefined exact geometrical model correlation for numerical simulations of IMC layer fracture. Thus, this paper aims to determine the accuracy of IMC layer models subjected to crack-to-width length ratio (a/W) in correlation with the ASTM E399-83 Srawley compact specimen model using finite element (FE) analysis. Several FE models with different geometrical configurations have been proposed under 10 MPa tensile loading. In this study, the two dimensional linear elastic displacement extrapolation method (DEM) is formulated to calculate the stress intensity factor (SIF) at the crack tip. The study showed that with an error of 0.58% to 0.59%, a width of 2.1 mm and a height of 1.47 mm can be recommended as the best geometrical model for IMC layer fracture modelling which provides a wider range for a/W from 0.45 to 0.85 instead of from 0.45 to 0.55. This result is significant as it presents a method for determining fracture parameters at thin IMC layers with a combination of singular elements with meshes at different densities which is tailored to the Srawley model.
  • Publication
    Finite element modelling of thin intermetallic compound layer fractures
    ( 2017)
    Ooi Eang Pang
    ;
    ; ; ;
    Mohd Shukry Abd Majid
    A thin intermetallic compound (IMC) of solder ball joint induces strong stress concentration between the pad and solder where a crack propagated near the IMC layer. The fracture mechanism of the IMC layer is complex due to the effect of IMC thickness, crack length, solder thickness and Young’s Modulus. At present, there is still an undefined exact geometrical model correlation for numerical simulations of IMC layer fracture. Thus, this paper aims to determine the accuracy of IMC layer models subjected to crack-to-width length ratio (a/W) in correlation with the ASTM E399-83 Srawley compact specimen model using finite element (FE) analysis. Several FE models with different geometrical configurations have been proposed under 10 MPa tensile loading. In this study, the two dimensional linear elastic displacement extrapolation method (DEM) is formulated to calculate the stress intensity factor (SIF) at the crack tip. The study showed that with an error of 0.58% to 0.59%, a width of 2.1 mm and a height of 1.47 mm can be recommended as the best geometrical model for IMC layer fracture modelling which provides a wider range for a/W from 0.45 to 0.85 instead of from 0.45 to 0.55. This result is significant as it presents a method for determining fracture parameters at thin IMC layers with a combination of singular elements with meshes at different densities which is tailored to the Srawley model.
  • Publication
    Influence of friction stir welding parameters on joint defects, temperature and hardness of AA6061-T6 and S27JR mild steel FSW joint
    The influence of welding parameters such as tool plunge depth, tool travel speed and tool tilt angle on welding temperature during friction stir welding of AA6061-T6 and S275JR mild steel was the focus of this research. Thermocouple placed in the aluminum alloy plate prior to welding was used to measure the temperature during the welding of joints under different set of parameter values. Joint appearance as well as defects occurring on the surface or within the joint was observed. Microhardness profiles were also taken by measuring microhardness values across the cross section of joints. Excessive flash, tunnel defects and insufficient welding were the type of weld defects observed on different joints with different parameters. Defects were attributed to the varied parameter values affecting the heat generation as well as the flow of the plasticized material. Highest temperature was recorded by the joint fabricated using the largest tool plunge depth, owing to the increased downwards pressure. Microhardness profiles were seen to be similar for all the welded joints. A “plateau” of low microhardness value was observed for all joints associated with the thermomechanically affected zone (TMAZ) and heat affected zone (HAZ). A wider plateau was observed for joints welded with higher tool plunge depth due to higher temperature.
  • Publication
    Tensile Properties of Diffusion Bonded Duplex Stainless Steel to Low Carbon Steel
    ( 2020-01-01)
    Baharudin B.A.
    ;
    Hussain P.
    ;
    Mustapha M.
    ;
    Ayob F.
    ;
    Ismail A.
    ;
    Ab Rahman F.
    ;
    Khalid P.Z.M.
    ;
    Hamid D.A.
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    The diffusion bonding is one of the methods used to join dissimilar metals. Specimens of duplex stainless steel and low carbon steel were joined by diffusion bonding under varied temperature and holding time. The specimens were clamped using jigs and heated in a furnace. Tensile test was performed on the joined samples. The effect of bonding time and holding temperature on tensile strength and quality of the diffusion bonds were observed. Tensile strength of the joints was examined and the highest tensile strength of 116.12 MPa are obtained at temperatures of 900 °C and holding time of 180 min.
  • Publication
    The Effect of Dry and Wet Condition on the Mechanical Properties of Hybrid Single Lap
    The aim of this study is to investigate the strength and mechanical behaviour of similar and dissimilar materials AA7075/E-glass single lap joint. The specimen radially in stack with Araldite epoxy adhesive and mechanical fasteners of Huck bolt with the bondline length of 64 mm for different joint configurations; bolted, bonded and hybrid. The investigation was conducted under two different conditions of dry and wet of 55°C for long water immersion of 120 days. The effect of moisture was defined in hybrid joints as combination of adherend and bonding materials. The tensile test with a speed rate of 1 mm/min was conducted for both condition using 100 kN load cell until total failure of specimen. The experimental results were plotted into load displacement and stress strain curve for each environment. In addition, failure mechanism of the specimens was detected in which occurred at adhesive and Huck bolt.
  • Publication
    Design and analysis of exhaust manifold for a single-cylinder internal combustion engine (ICE)
    ( 2021-05-24)
    Aziz N.A.
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    Rahman M.T.A.
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    Amin N.A.M.
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    ; ;
    Nasir N.F.M.
    ;
    Rahman Y.M.N.
    An efficient exhaust system is vital to maximising the performance of an internal combustion engine (ICE), hence improving overall vehicle performance. To have an efficient exhaust system, the amount of exhaust backpressure is to be minimised. To decrease the backpressure effects in the exhaust system, the exhaust has to be redesigned according to the certain bending radius, length of straight pipe and bending angle and pipe diameter. This paper presents design and analysis of the exhaust system used in Shell Eco-Marathon 2019 competition. In this project, the exhaust manifold was redesigned according to the specification of the chassis, the exhaust outlet in the engine and the rules and regulations of the competition. Computational Fluid Dynamic (CFD) analysis was employed to identify the optimum exhaust system design with minimum pressure loss. Among the tested models, the exhaust manifold with 100 mm length, 30° bending angle, 34 mm diameter, and 40 mm bending radius was the optimised design that resulted in the lowest pressure loss of 12.24 kPa. This study shows that a small bending angle with a short straight pipe has led to a smoother exhaust flow and even exhaust velocity across the model.
  • Publication
    Convergence and stress analysis of the homogeneous structure of human femur bone during standing up condition
    Finite element models have been widely used to quantify the stress analysis and to predict the bone fractures of the human body. The present study highlights on the stress analysis of the homogeneous structure of human femur bone during standing up condition. The main objective of this study is to evaluate and understand the biomechanics for human femur bone and to prepare orthotropic homogeneous material models used for FE analysis of the global proximal femur. Thus, it is necessary to investigate critical stress on the human femur bone for future study on implantation of internal fixator and external fixator. The implication possibility to create a valid FE model by simply comparing the FE results with the actual biomechanics structures. Thus, a convergence test was performed by FE model of the femur and the stress analysis based on the actual biomechanics of the human femur bone. An increment of critical stress shows in the femur shaft as the increasing of load on the femoral head and decreasing the pulling force at greater trochanter.
  • Publication
    Experimental investigation on the failure of T-joints at elevated temperature under unaxial loading
    ( 2017-09-26)
    Nahdiyatunnisa Bahri
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    ; ;
    Nor Bakyah Abu
    ;
    Setno Baharuddin
    In this study, the mechanical properties and maximum failure load of a bulk and T-joints subjected to tensile loading were investigated experimentally. A bulk and the T-joint specimens were fabricated and tested in order to investigate the effects of temperature conditions on the failure of the joints. The adherent and adhesive used for T-joint are 304 L stainless steel and Hysol E 214 HP with the adhesive thickness of 1.0 mm. The tensile test of the bulk specimen and adhesively T-joint were conducted by using a universal testing machine (UTM) at room temperature (RT), 55 °C, 75 °C, 100 °C and 120 °C, respectively. It was found that as the temperature increases, the failure force strength decreases for bulk and T-joint specimen. Data obtained from the tests at 120 °C showed the failure force of the bulk adhesive decreased by approximately 44 % compared to the specimen tested at RT. Next, the bulk of Hysol failure force result was compared with Araldite at RT and 100 °C. Araldite data was taken from the previous study [1]. It has also been found that the bulk for Hysol has higher failure force compared to Araldite at RT and 100 °C.
  • Publication
    Three Dimensional Finite Element Analysis of Rolling Contact between Wheel and Rail
    ( 2017-09-06)
    Gurubaran Panerselvan
    ;
    ;
    Haftirman I.
    ;
    Nanthini Kanasan
    The fatigue performance of the rails is affected by many factors, including service conditions, loading, mechanical properties, environment factors, and manufacturing processes. In this paper, the investigation on wheel-rail to identify the initial damages caused by Rolling Contact Fatigue (RCF) cracks and the location that experienced damages is presented. UIC 54kg rail (grade 900A) was used as the model in three dimensional (3D) finite element contact analysis. The fatigue crack growth on wheel-rail was carried out by considering the Hertz contact pressure. The finite element analysis results show that maximum stress concentration zone was between the wheel-rail surface (rail inside curve gauge corner) and it is above the yield stress limit for wheel-rail steel. Fatigue crack propagation within a depth affected stress concentration region was predicted. The stress intensity factors (SIF) for mode I, mode II and mode III fracture were plotted from ANSYS simulation. Three types of fracture modes were affected the UIC54kg rail Steel to fail or develop initial failure when the crack propagation exceeds 5 mm.