Applied Mechanics and Materials Vol. 786

Abstract: A research study on the fatigue performance of hybrid adhesive joints was carried out to investigate the fatigue performance of adhesive joint and hybrid adhesive joint using dissimilar material. A 3 mm thin plate of aluminium A7075 and stainless steel 304 are used as the adherend material for experimental test and the adhesive used was high performance Araldite epoxy adhesive. Maximum fatigue life was achieved for the hybrid adhesive joint with an optimum overlap length of 59 mm and the adhesive thickness of 0.2 mm. The fatigue damaged occurs on the adherend surface for adhesive joint and adherend crack for hybrid adhesive joint. Results showed an increment of fatigue life with shear stress reduction.

Abstract: In this study, adhesive T-joint with crack in urea granulator fluidization bed was analyzed by finite element (FE) analysis. Objectives of this project were to examine a series of adhesively bonded T- joints with crack under mode I loading, to evaluate stress analysis of adhesive T-joint with crack at top and bottom and to identify the effective bond thickness. The path was drawn in ANSYS at the top and bottom of adhesive from side view to find which part has higher stress. The result of both paths top and bottom analysis shows the stress distribution always higher at both edges. So, the crack was inserted at interface edges and the stress distribution was evaluated. From interface edges stress distribution result of top and bottom, it shows that bottom edge has higher stress compare with top edge. The failure load analysis will compare with other analysis and experiment result. It is found that adhesive T-joint with 1.5mm is the best thickness for granulator fluidization bed application because always has higher failure load.

Abstract: This study aims to investigate the effect of three factors, namely alumina trihydrate (ATH), montmorillonite (MMT) and irradiation dosage on the mechanical properties (tensile strength and elongation at break) of flame-retarded LDPE-EVA composites. In this study, full factorial design analysis was used to examine the effects of factors and their combination interactions on mechanical properties. ATH is the most significant factor in affecting the tensile strength of LDPE-EVA blends due to the poor compatibility effect between ATH particles and LDPE-EVA matrix. However, MMT is the least significant factor on tensile strength of LDPE-EVA composites. ATH was the most significant in affecting the elongation at break of LDPE-EVA blends. This is because the increasing of ATH amount in LDPE-EVA matrix could restrict the mobolity of polymer chains in LDPE-EVA matrix. However, the factor of irradiation dosage was found to be insignificant in affecting the elongation at break of LDPE-EVA blends.

Abstract: In this research study, the effect of aging duration time and electron beam irradiation dosages on the hot set results of copper (II) oxide added LDPE composites have been investigated. The addition of copper (II) oxide particles in LDPE matrix has significantly reduced the formation of crosslinking networks in LDPE matrix by blocking the mobility of free radicals generated by electron beam irradiation. At lower irradiation dosages (< 100 kGy), all the copper (II) oxide added LDPE composites were immediately failed the hot set test when subjected to static load of 20 N/cm2 under high temperature. Besides, the occurrence of copper (II) oxide particles in LDPE matrix also reduced the matrix continuities of copper (II) oxide added LDPE composites and caused the matrix resistance ability of LDPE matrix to be decreased. The increasing of irradiation dosages has significantly delayed the failing time of all LDPE composites when under static load at high temperature. This is because the increasing of electron beam irradiation could further induce the generation of free radicals to form higher degree of crosslinking networks in LDPE matrix. At higher irradiation dosage up to 250 kGy, the pristine LDPE was observed able to withstand the applied static load under high temperature more than 15 minutes. This is due to higher degree of crosslinking networks formed in LDPE matrix could effectively restrict the mobility of LDPE chains under static load and thus delay the failing of sampels. When the aging duration time increased from 4 days to 14 days, the resistance ability of all LDPE has been significantly weakened due to the occurrence of chain scissioning process in LDPE matrix by delaying the failing time of samples.

Abstract: This paper presents a literature review on the influence of heat treatment and surface roughness to the adherent surface and its effect on adhesion strength and covers some article published from 1992 to 2013. The paper is divided into several related topics such as types of adhesive bonding failure, effect of surface roughness, and effects of heat treatment. The objective of this paper is to reveal the underlying scientific phenomena, relationships, and arguements on the related topics. The paper is concluded by highlighting the significant topics that drives future research.

Abstract: The mechanical properties of fibre reinforced polymer composites strongly depend on the interfacial bonding between fibre and matrix. The main objective of this paper is to compare the interfacial bonding between kenaf fibre reinforced POM with that of PET fibre reinforced POM in a hybrid composite. Continuous twisted kenaf, and PET yarn were used for the investigation. Each fibre yarn was half embedded in POM by compression moulding. The yarns were extracted from the matrix by single fibre pull out test method. The result of the investigation revealed that the interfacial shear strength of approximately 31.4 MPa between kenaf and POM is higher compared to 24.3 MPa obtained between PET fibre and POM. This may be due to higher surface energy of kenaf fibre with respect to POM in the composite The FESEM micrograph further demonstrates good interfacial adhesion between kenaf and POM in the composite.

Abstract: Failure behaviour of aircraft sandwich panels under bending load has been investigated in this study. Three-points bending test was performed to the specimens with various span-to-thickness (S/d) ratios 32, 40, and 60. Testing method and dimension of specimens were adhering to the American Society for Testing and Materials (ASTM) D-790M. Deflection and energy absorption of the sandwich panels was characterized by specific span-to-thickness (S/d) ratios. It was found that specimen with S/d of 40 has the steepest slope in stress-strain curve and specimen with S/d of 32 has the highest flexure strength, 831MPa. The flexure strength decreases with the increasing of span-to-thickness ratio. The result shows that the increasing of the span-to-thickness ratio increased the crack length at the lowest maximum bending stress, 636 MPa. The results suggest that the performance of the Carbon Fiber Reinforced Epoxy (CFRE) composites is strongly influenced by the crack length.

Abstract: Greenhouse effects were generated from anthropogenic emissions of carbon dioxide (CO₂) into the atmosphere. High concentration of CO₂ has recognised as major causes of global warming. In order to keep CO₂ at a manageable level, adsorptions of these gases from the flue gases is necessary. Developing a low cost porous solid adsorbent as adsorption media become a great attention due to environmental and economic concerns. This paper has reviewed the cost effective materials with a suitable methods to fabricate the porous solid adsorbent. This paper also has discussed the adsorption mechanisms of CO₂ on the selective cost effective materials.

Abstract: The objective of this paper is to obtain fatigue properties of API X65 steel using the stress life (S-N) approached. In this method S-N curve was established by relating the applied load and the number of cycles to failure. The sets of data were successfully constructed within the range of high and low cycle domains. The fully reversed loading was employed to generate the most severe damage condition. The experiment data lies approximately within correlation boundaries of 1:2 and 2:1. The mean square error was performed to evaluate the goodness of experiment to the simulated data. Therefore, with a 21% of accuracy it was concluded the presented data taken from actual measurements can be used for life prediction of X65 steel.

Abstract: The use of adhesive structural in joining application offers the great demand due to its many advantages such as lightweight structures and flexible design. However, moisture provides significant problem and adverse effect on degrading the adhesive. The strength of the adhesive reduces because mechanical properties are known to reduce also with moisture environment. Therefore, this paper discusses about the adhesive T-joint test on specimen within moisture condition and specimen without moisture, at room temperature. Additionally, this study also analyses the failure stress when load is applied for both exposed conditions. Bulk specimens are compressed at room temperature, specimen without immersing in hot water, RT and specimen with immersing in three hot water conditions 80°C, 90°C, and 100°C at a constant time of 15 minutes. The adhesive of a 1.0mm thickness has been set for T-joint tensile test. Compression test revealed that mechanical properties of Young’s modulus decreased with the increase of water temperature. Experimental results indicated that the failure stress of adhesive T-joint at room temperature and 90°C was higher compared to that of specimen soaked in 80°C and 100°C of hot water. The behaviour of adhesive joint tests under static loading analysis of experiments and the finite element analysis using ANSYS 14.0 software have shown good agreement.