In this study, strength of epoxy adhesively bonded scarf joints of dissimilar adherends, namely SUS304 stainless steel and YH75 aluminium alloy is examined on several scarf angles and various bond thicknesses under uniaxial tensile loading. Scarf angle, θ = 45º, 60º and 75º are employed. The bond thickness, t between the dissimilar adherends is controlled to be ranged between 0.1 mm and 1.2 mm. Finite element (FE) analysis is also executed to investigate the stress distributions in the adhesive layer of scarf joints by ANSYS 11 code. As the results, the apparent Young's modulus of adhesive layer in scarf joints is found to be 1.5 ~ 5 times higher than those of bulk epoxy adhesive, which has been obtained from tensile tests. For scarf joint strength prediction, the existing failure criteria (i.e. maximum principal stress and Mises equivalent stress) can not satisfactorily estimate the present experimental results. Though the measured stress multiaxiality of scarf joints proportionally increases as the scarf angle increases, the experimental results do not agree with the theoretical values. From analytical solutions, stress singularity exists most pronouncedly at the steel/adhesive interface corner of joint having 45º to 75º scarf angle. The failure surface observations confirm that the failure has always initiated at this apex. This is also in agreement with stress-y distribution obtained within FE analysis. Finally, the strength of scarf joints bonded with brittle adhesive can be best predicted by interface corner toughness, Hc parameter.

A laboratory-based experiment procedure of reception plate method for structure-borne sound source characterisation is reported in this paper. The method uses the assumption that the input power from the source installed on the plate is equal to the power dissipated by the plate. In this experiment, rectangular plates having high and low mobility relative to that of the source were used as the reception plates and a small electric fan motor was acting as the structure-borne source. The data representing the source characteristics, namely, the free velocity and the source mobility, were obtained and compared with those from direct measurement. Assumptions and constraints employing this method are discussed.

The over-reliance and environmental damage caused by the use of fossil fuels have created the need to explore an alternative source of renewable and clean energy. Free Fatty Acid (FFA) from Hevea brasiliensis oil or commonly known as rubber seed oil (RSO) was utilized as feedstock with the aid of waste mollusk shells (Perna viridis) using domestic household batch microwave irradiation technique. The mollusk shells were sieved to particles sizes ranging from 1 mm to 2 mm and were calcined at 900 o C for 4 hours at 5 o C/min heating rate. SEM-EDS, XRF, and XRD were performed to characterize the surface morphologies and composition of the catalyst. The two-step esterificationtransesterification process reduced the total acid number of RSO from 104.70 mg KOH/g to 0.463 mg KOH/g. The optimum yield of fatty acid methyl ester (FAME) reached up to 96.6% under optimal conditions of 12:1 methanol molar ratio, catalyst loading of 12 weight percent (wt%) oil, 7 minutes of reaction time, and 400-Watt microwave power input. The produced methyl ester fatty acids composition was analyzed via GC-MS and the physicochemical properties such as kinematic viscosity, acid value, flash point, density, water content, and calorific value were analyzed according to the American Society for Testing and Materials D6751 (ASTM D6751) and European Committee for Standardization (EN 14214) and were found to be within the requirements.

Simple analytical model of plate dynamics usually applies for rectangular plate with simply supported edges. Analytical model of sound radiation from rectangular plate is also convenient, but not for other geometries and other boundary conditions. This paper presents a hybrid mathematical model which combines a semi-analytical model with the Finite Element Analysis (FEA) method to determine sound radiation from a vibrating structure. The latter is employed to calculate the vibration velocity of a structure with a rather complex geometry. The results are then used as the input in the semi-analytical model to calculate the radiated sound pressure through the Rayleigh integral. Results from the proposed model are presented here for the radiation efficiency of rectangular plates with different boundary conditions.

This paper presents the estimation of vibration strength obtained from reception structure method. It describes a laboratory-based measurement procedure, which determines the strength of a vibration source in terms of its total squared free velocity. The source used in the experiment is a small electric fan motor. Here instead of using the usual flat rectangular plate, a thin stainless steel beam was used as the reception structure. The aim is to validate the data obtained from the reception method with that from the direct measurement. A good agreement is found between the two results, although small discrepancies occur due to the modal behavior of the beam.