Applied Mechanics and Materials Vol. 786

Abstract: This paper presents the experimental investigation on adhesive joint under three loading angles using a modified Arcan jig. Fracture test was performed using the fabricated Arcan specimens and Araldite adhesive with loading angle of 0°, 90° and 45° to represent Mode I, Mode II and mixed Mode loading, respectively. Eighteen specimens were prepared with adhesive thickness of 6 mm and nine of them with interface crack length of 5 mm. The result shows the stress intensity factor, K is influenced by the loading angle and the initial crack-line directions. KI was found greater than KII .

Abstract: In this work, the effect of aging duration time and copper (II) oxide loading level on the physico-mechanical properties of copper (II) oxide added LDPE composites have been investigated. The addition of copper (II) oxide particles in LDPE matrix has significantly decreased the tensile strength of LDPE composites. The occurrence of copper (II) oxide particles in LDPE matrix could reduce the matrix continuities of copper (II) oxide added LDPE composites by the agglomeration of copper (II) oxide particles. This could further cause the applied straining stress unable to be effectively transferred throughout the whole polymer matrix. The increasing of aging time duration up to 8 days has slightly reduced the tensile strength of all copper (II) oxide added LDPE composites. The increasing of copper (II) oxide loading level has significantly decreased the elongation at break of LDPE composites. This is due to poor interfacial adhesion between copper (II) oxide particles and LDPE matrix could further restrict the mobility of LDPE chains under straining stress and thus decrease the elongation at break.

Abstract: In this study, the effect of aging time duration in acidic solution and electron beam irradiation on the physical and mechanical properties of copper (II) oxide added LDPE composites haven been investigated. The tensile strength of all (3 phr and 5 phr) copper (II) oxide added LDPE composites was gradually increased with increasing of electron beam irradiation dosages from 0 kGy to 200 kGy. The electron beam irradiation could induce the formation of crosslinking networks in LDPE matrix by increasing the resistance ability of LDPE matrix towards applied straining stress. The increasing of aging time duration in acidic condition up to 4 days has marginally reduced the tensile strength of all un-irradiated and irradiated all copper (II) oxide added LDPE composites. This might be attributed to the hydrochloric acid solution could degrade and breakdown the macromolecular chains in LDPE matrix and thus further reduce the tensile strength of copper (II) oxide added LDPE composites.

Abstract: This paper describes a study on the effects of heat treatment on the microstructure, hardness and wear of aluminum alloys 332 (AlSi₉Cu₃Mg). The solution treatment was performed at 500°C for 5 hours and then quenched in water at room temperature. Aging was performed at 170°C for 2 hours. The findings revealed that after a full heat treatment, the structure of the eutectic silicon formed toward fragmentation and spheroidization, and the silicon particles became coarse (look-like rounded). Hard intermetallic compound (Mg₂Si) appeared on the microstructure after the aging treatment completed. Compared to the as-cast, the hardness of the alloys has improved to 44.84%, and the wear rate of the solution treatment had decreased to 26% while the aging treatment showed a deterioration of 79.42%. The study concludes that aging treatment improves the hardness of AA332 alloys and enhanced the wear resistance of the substance.

Abstract: This paper presents an experimental investigation of the effects of alkaline treatment on the tensile properties of Napier grass fibres. The effect of different concentrations of NaOH aqueous solutions on the morphology and structure of the fibres were studied. The fibres were treated with 5%, 10%, and 15% of Sodium hydroxide (NaOH) concentration for 24 hours of soaking time. The single fibre tests were then performed in accordance with ASTM D3822-07 standard. The morphology of the fibres before and after alkali treatment was observed with a Metallurgical Microscope MT8100. The results show that the physical properties were varied after the treatments and 10% concentration of NaOH treatment yield the maximum tensile strength and elongation of the fibre at 172 MPa and 5.7% respectively. Morphology observation found that the fibre became thinner, and the surface roughness of the fibres increased with the increment of NaOH concentration.

Abstract: This paper describes the effect of weight contents of fillers on the compression properties of the Napier grass filler-filled polyester resin. Unsaturated polyester resins with 0, 1, 3, 5 wt% Napier fibre based fillers were prepared through manually mixing process in accordance with ASTM D695 for compressive test. The static unaxial compressive tests were conducted using a Shimadzu Universal Testing Machine with a thermostatic chamber at temperatures ranging from room temperature (RT) to the temperature close to its glass transition temperature Tg (RT, 35, 55, 75 °C). The result shows that the elastic modulus and compressive strength of the modified resin were significantly affected by Napier fibre based filler contents and temperatures. It was found that the specimens showed reductions in compressive strength with increases in temperatures.

Abstract: Elasto-plastic tensile deformations in multi-colony structures are studied by finite element analyses to investigate how the deformation in multi-colony structures influence the strain concentration around colony boundary. The results obtained from plastic strain distributions show that plastic strain concentrates around colony boundary when there is a large difference of deformation between adjacent colonies and around the point where boundaries of differently aligned colonies meet.

Abstract: This study evaluates the effect of temperature upon adhesive properties and behavior of adhesively bonded T-joint. Finite element analyses established the effect of this parameter on the durability joint and stress distribution within the adhesive layer. A series of temperatures and stress analyses using finite element analysis (FEA) has been conducted in the T-joint configuration for this purpose. The parametric studies on the FE model revealed that stress distributions are sensitive to the changes in adhesive properties due to changes in temperature. In general, stresses were reduced with changes in the temperature which resulted in the ability of the adhesive layer to undergo plastic deformation.

Abstract: Automotive industries are looking for new implementation to deliver a good finishing product to their customer. By using adhesive material, joining against two steel can replace normal technique which is welding process. However, the strength produced by this method must be investigated. The failure investigation of ductile adhesive intended for use in automotive tubular frame chassis has been assessed using simple tubular lap shear joint. There are two different overlap lengths of tubular adhesive joint considered in this test, i.e., 15 mm and 45 mm. The materials used for the adherents were stainless steel and mild steel, while adhesive used in the experiments was Araldite Standard 90 minutes epoxy resin. Tensile test by utilizing universal testing machine (UTM) was carried out to determine the shear strength of the adhesive joint in different overlap length. Fatigue tests were also conducted. From the results it is found that longer overlap length of the adhesive is preferable for use in automotive tubular frame chassis due to higher failure load it can withstand and better fatigue life.