Mohd Afendi Rojan
Thumbnail Image
Preferred name
Mohd Afendi Rojan
Official Name
Mohd Afendi , Rojan
Alternative Name
Afendi, Mohd
Rojan, M. Afendi
Afendi Rojan, M.
Afendy, M.
Rojan, M. A.
Mohd Afendi, R.
Afendi, M.
Main Affiliation
Scopus Author ID
57188766103
Researcher ID
GQR-0248-2022

Research Output

Filters

10
Reset filters

Settings
Now showing 1 - 10 of 10
Thumbnail Image
Publication

Finite element modelling of thin intermetallic compound layer fractures

2017 , Ooi Eang Pang , Ruslizam Daud , Nasrul Amri Mohd Amin , Mohd Afendi Rojan , Mohd Shukry Abdul 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.

View
Thumbnail Image
Publication

Energy release rate analysis on the interface cracks of enamel-cement-bracket fracture using virtual crack closure technique

2017-10-29 , Syafiq Farhan Samshuri , Ruslizam Daud , Mohd Afendi Rojan , Fauziah Che Mat , Khairul Salleh Basaruddin , Rozita Hassan

This paper presents the energy method to evaluate fracture behavior of enamel-cement-bracket system based on cement thickness. Finite element (FE) model of enamel-cement-bracket was constructed by using ANSYS Parametric Design Language (APDL). Three different thickness were used in this study, 0.05, 0.2, and 0.271 mm which assigned as thin, medium and thick for both enamel-cement and cement bracket interface cracks. Virtual crack closure technique (VCCT) was implemented as a simulation method to calculated energy release rate (ERR). Simulation results were obtained for each thickness are discussed by using Griffith's energy balance approach. ERR for thin thickness are found to be the lowest compared to medium and thick. Peak value of ERR also showed a significant different between medium and thick thickness. Therefore, weakest bonding occurred at low cement thickness because less load required to produce enough energy to detach the bracket. For medium and thick thickness, both increased rapidly in energy value at about the mid-point of the enamel-cement interface. This behavior occurred because of the increasing in mechanical and surface energy when the cracks are increasing. However, result for thick thickness are higher at mid-point compared to thin thickness. In conclusion, fracture behavior of enamel cracking process for medium most likely the safest to avoid enamel fracture and withstand bracket debonding.

View
Thumbnail Image
Publication

Experimental and finite element analysis on ratchetting behaviour of glass fibre reinforced epoxy composites under cyclic loading

2017-02-01 , Khairul Salleh Basaruddin , Ruslizam Daud , Mohd Shukry Abdul Majid , Mohd Afendi Rojan , Ishak Ibrahim

This study aims to examine the uniaxial and biaxial ratchetting responses of glass fibre reinforced epoxy (GRE) composite by experiment and finite element (FE) analysis. The uniaxial ratchetting of GRE composite laminate was tested under cyclic axial stress with a constant mean stress of 40 MPa and an amplitude stress between 26.67 MPa and 53.33 MPa. The biaxial ratchetting test was also performed on 50 mm diameter of GRE composite straight pipe. The GRE pipe was subjected to a constant internal pressure of 1.875 MPa and 1% of cyclic axial strain. The FE models were simulated using Abaqus in similar loading cases. The uniaxial ratchetting strain was found to increase with the number of cycles, but the ratchetting strain rate was decreased. The specimen showed no further ratchetting and exhibited shakedown after some strain accumulation. On the basis of the experiment and simulation in the biaxial test, it appears that ratchetting would occur in the hoop direction for a GRE pipe with no ratchetting observed in the axial direction. The results showed that the FE analysis over-predicts the ratchetting rate for uniaxial ratchetting test as compared to the experimental values, but under-predicts in the biaxial ratchetting test at initial cycles.

View
Thumbnail Image
Publication

Finite element modelling of thin intermetallic compound layer fractures

2017-03-01 , Ooi Eang Pang , Ruslizam Daud , Nasrul Amri Mohd Amin , Mohd Afendi Rojan , Mohd Shukry Abdul 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.

View
Thumbnail Image
Publication

Finite element modelling of thin intermetallic compound layer fractures

2017 , Ooi Eang Pang , Ruslizam Daud , Nasrul Amri Mohd Amin , Mohd Afendi Rojan , 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.

View
Thumbnail Image
Publication

Stress analysis of implant-bone fixation at different fracture angle

2017-10-29 , Izzawati Basirom , Ruslizam Daud , Mohd Afendi Rojan , Mohd Shukry Abdul Majid , Noor Alia Md Zain , Mohd Yazid Bajuri

Internal fixation is a mechanism purposed to maintain and protect the reduction of a fracture. Understanding of the fixation stability is necessary to determine parameters influence the mechanical stability and the risk of implant failure. A static structural analysis on a bone fracture fixation was developed to simulate and analyse the biomechanics of a diaphysis shaft fracture with a compression plate and conventional screws. This study aims to determine a critical area of the implant to be fractured based on different implant material and angle of fracture (i.e. 0°, 30° and 45°). Several factors were shown to influence stability to implant after surgical. The stainless steel, (S. S) and Titanium, (Ti) screws experienced the highest stress at 30° fracture angle. The fracture angle had a most significant effect on the conventional screw as compared to the compression plate. The stress was significantly higher in S.S material as compared to Ti material, with concentrated on the 4th screw for all range of fracture angle. It was also noted that the screws closest to the intense concentration stress areas on the compression plate experienced increasing amounts of stress. The highest was observed at the screw thread-head junction.

View
Thumbnail Image
Publication

Fracture behavior of intermetallic compound (IMC) of solder joints based on finite elements’ simulation result

2017-01-01 , Eang Pang Ooi , Ruslizam Daud , Nasrul Amri Mohd Amin , Fauziah Che Mat , Sulaiman M.H. , Mohd Shukry Abdul Majid , Mohd Afendi Rojan , Ahmad Kamal Ariffin

The development of microelectronic industry has made solder joints failure a major reliability issue. From literature, many researchers have identified that intermetallic compounds (IMC) layer contribute greatly to the fracture of solder joint. This paper presents a finite element modeling of solder butt joints IMC layer failure based on displacement extrapolation method (DEM). Conceptual study on single edge crack of IMC solder joints is presented. A FE analytical model is proposed to be used in difference range of crack length to understand the fracture behavior of solder joint of IMC layer. The simulation results show that soldering material become less tough if greater crack length is present in the joint. It also seen that the thicker IMC has slightly reduced the stress intensity factor on the crack tip but the change from solder to IMC layer decrease the solder joint fracture toughness.

View
Thumbnail Image
Publication

Convergence and stress analysis of the homogeneous structure of human femur bone during standing up condition

2017-09-26 , Izzawati Basirom , Ruslizam Daud , Mohd Afendi Rojan , Mohd Shukry Abdul Majid , Noor Alia Md Zain

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.

View
Thumbnail Image
Publication

Convergence study of global meshing on enamel-cement-bracket finite element model

2017-09-26 , Syafiq Farhan Samshuri , Ruslizam Daud , Mohd Afendi Rojan , Khairul Salleh Basaruddin , Abdullah A.B. , Ahmad Kamal Ariffin

This paper presents on meshing convergence analysis of finite element (FE) model to simulate enamel-cement-bracket fracture. Three different materials used in this study involving interface fracture are concerned. Complex behavior ofinterface fracture due to stress concentration is the reason to have a well-constructed meshing strategy. In FE analysis, meshing size is a critical factor that influenced the accuracy and computational time of analysis. The convergence study meshing scheme involving critical area (CA) and non-critical area (NCA) to ensure an optimum meshing sizes are acquired for this FE model. For NCA meshing, the area of interest are at the back of enamel, bracket ligature groove and bracket wing. For CA meshing, area of interest are enamel area close to cement layer, the cement layer and bracket base. The value of constant NCA meshing tested are meshing size 1 and 0.4. The value constant CA meshing tested are 0.4 and 0.1. Manipulative variables are randomly selected and must abide the rule of NCA must be higher than CA. This study employed first principle stresses due to brittle failure nature of the materials used. Best meshing size are selected according to convergence error analysis. Results show that, constant CA are more stable compare to constant NCA meshing. Then, 0.05 constant CA meshing are tested to test the accuracy of smaller meshing. However, unpromising result obtained as the errors are increasing. Thus, constant CA 0.1 with NCA mesh of 0.15 until 0.3 are the most stable meshing as the error in this region are lowest. Convergence test was conducted on three selected coarse, medium and fine meshes at the range of NCA mesh of 0.15 until 3 and CA mesh area stay constant at 0.1. The result shows that, at coarse mesh 0.3, the error are 0.0003% compare to 3% acceptable error. Hence, the global meshing are converge as the meshing size at CA 0.1 and NCA 0.15 for this model.

View
Thumbnail Image
Publication

Stability Analysis of Plate—Screw Fixation for Femoral Midshaft Fractures

2023-09-01 , Basirom I. , Ruslizam Daud , Ijaz M.F. , Mohd Afendi Rojan , Khairul Salleh Basaruddin

An understanding of the biomechanical characteristics and configuration of flexible and locked plating in order to provide balance stability and flexibility of implant fixation will help to construct and promote fast bone healing. The relationship between applied loading and implantation configuration for best bone healing is still under debate. This study aims to investigate the relationship between implant strength, working length, and interfragmentary strain (εIFM) on implant stability for femoral midshaft transverse fractures. The transverse fracture was fixed with a fragment locking compression plate (LCP) system. Finite element analysis was performed and subsequently characterised based on compression loading (600 N up to 900 N) and screw designs (conventional and locking) with different penetration depths (unicortical and bicortical). Strain theory was used to evaluate the stability of the model. The correlation of screw configuration with screw type shows a unicortical depth for both types (p < 0.01) for 700 N and 800 N loads and (p < 0.05) for configurations 134 and 124. Interfragmentary strain affected only the 600 N load (p < 0.01) for the bicortical conventional type (group BC), and the screw configurations that were influenced were 1234 and 123 (p < 0.05). The low steepness of the slope indicates the least εIFM for the corresponding biomechanical characteristic in good-quality stability. A strain value of ≤2% promotes callus formation and is classified as absolute stability, which is the minimum required value for the induction of callus and the maximum value that allows bony bridging. The outcomes have provided the correlation of screw configuration in femoral midshaft transverse fracture implantation which is important to promote essential primary stability.

View