Applied Mechanics and Materials Vol. 372

Abstract: The fretting wear behavior of Ti-6Al-4V is studied with the focus on cyclic plasticity effect under gross sliding condition. The analysis is simulated using finite element based method with a new surface profile model represently a given number of cycles using a cylinder-on-flat geometry. The effect of cyclic plasticity on the stresses and plastic strain distribution is studied. The maximum tangential stress is predicted at the trailing edge while the maximum compressive tangential stress is predicted at the leading edge of contact area. Plasticity in shear component is significant compare to tangential component and predicted at 0^th and 3000^th cycles only. It is found that important to include plasticity that remains from previous cycle for better prediction of fretting wear.

Abstract: Product development cycle time is very important in automotive industry which is very competitive nowerdays. New products are introduced into the market with better designs in short period of time by carrying out different engineering analysis. This study is focused on analyzing the existing chassis design and the noise, vibration and harshness(NVH) characteristics are studied. Modeling of chassis structure is carried out using 3D modelling package CATIA V5 and finite element model is created by meshing using Hypermesh software. The main objective is to find the natural frequency and analyse the mode shape of the automotive chassis structure. Results of the analysis will help to study the dynamic behavior of the chassis structure with load application/real road condition and to improvise the car chassis structure assembly.

Abstract: One of the oldest suspension components that are still in use, especially in commercial vehicles, is leaf springs. Due to high strength to weight ratio, the automobile industries have shown interest in replacing steel springs with composite leaf springs. This work is carried out on multi leaf springs having nine leaves, used in commercial vehicle. A Finite element approach for analysis of a multi leaf springs using ANSYS software is carried out. The model is generated using solid works and imported in ANSYS. The material of the leaf springs is 65Si7 (SUP9), composite leaf springs and hybrid leaf springs. Fatigue analysis of leaf springs is carried out for steel leaf springs, and Static analysis for steel leaf springs, composite leaf springs and hybrid leaf springs.

Abstract: According to the special structure of DCT, the control strategy of launch with two clutches has been proposed to share the friction work and extend the life of both clutches. The dynamic model of launch with two clutches and the clutch control model have been built. the control strategies of both clutches have been proposed respectively according to the requirement of the different driver intention and the limitation of the impact of vehicle. The simulation model of launch with two clutches has been built using the Matlab/Simulink platform, and the simulation has been carried out. The Simulation results show that the balance of friction work based on this launch strategy with two clutches has been validated.

Abstract: According to the principle of tri-branching, a mechanism structural model was developed to analyze the helical gear transmission system. On the base of loaded tooth contact analysis (LTCA), the load transmission error of each gear stage is simulated at the any engagement position, and the fitting curves of the torsion mesh stiffness are obtained, which can improve the numerical precision. The research results can be applied to analyze the actual application of tri-branching transmission system and provide a firm foundation for study the power-split and load-sharing characteristics.

Abstract: According to the loading feature and the structure form, a gear reducer box can be simplified to a variable cross-section cylindrical shell structure excited by multipoint force. Meanwhile, a theoretical model is developed to analyze the structural vibration and acoustic characteristics and to find out the dominant component of vibration. Then, the influence of different parameters, such as, the local structure thickness, constrained damping layer and the insulation layer on acoustic radiation performance of the variable cross-section cylindrical shell structure are investigated by numerical calculation. Finally, an optimization design scheme of a low-noise structure is proposed because of the two aspects about noise source and noise transfer path.

Abstract: We organized a project of solar cells in University of Miyazaki in order to develop the technologies for solar cells. We have four kinds PV module systems, such as hybrid Si Thin film (1 kW), Poly-Si (50 kW), CIS (100 kW) and CPV (14 kW×2). Their total is 179 kW. These take appoximately 5% of total electricity of the university.

Abstract: A thermal emission layer was coated on the aluminum chassis of a concentrator photovoltaic (CPV) module. The cell temperature in the CPV mini-module with the white thermal emission coating was 3 - 5°C lower than that in the CPV mini-module without the thermal emission coating. The effect of the high-radiation layer was remarkable. In spite of the high emissivity of the black thermal emission coating, the effect of the black coating was not remarkable. This is because the scattered light from environment is absorbed by the black coating and the CPV mini-module is heated. The color of CPV is important and the white coating is better than the black coating.

Abstract: CuInS₂ (CIS) is the promising candidate of an absorber layer of high efficiency thin film solar cells. The crystal quality of CIS is one of the important factors for high efficiency. A chemical doping approach using antimony and bismuth (Bi) is well known for improving crystal quality in Cu (In,Ga)Se₂ thin films. In this study, the effect of Bi doping on evaporated CIS thin films was investigated. A CIS thin film without Bi doping annealed at 600°C showed small crystal grain size of ~1 μm, which was smaller than the CIS film thickness of 2 μm. The small addition of 50 nm-thick Bi promoted crystal growth and large grain size of greater than 1 μm, which was comparable to the CIS film thickness, was realized. The CIS films without and with Bi addition had surface precipitates identified as Cu-S and Cu-Bi-S compounds, respectively. The crystal growth promotion by Bi addition can be attributed to that the Cu-Bi-S compound which has lower melting point of 470~490°C than that of the Cu-S compound of 507°C acted as flux for crystal growth.

Abstract: Zn (O,S):Al (AZOS) has been proposed as a new type of transparent conductive oxide (TCO) with adjustable band gap energy (E_g) and conduction band position. The novel materials of AZOS with S/(S+O) ratio of 0.00~0.85 were prepared by radio frequency magnetron co-sputtering of ZnO:Al and ZnS targets. The optical properties of the films showed high transmittance of almost over 80% and E_g change with the S/(S+O) ratio. The suitable resistivity for TCO of around 10^-3 Ωcm was obtained at the S/(S+O) ratio of 0.00~0.09, but as the S/(S+O) ratio exceeded 0.40, the resistance increased greatly.