Applied Mechanics and Materials Vol. 680

Abstract: The petiole’s fracture of mine-used explosion-proof axial fan has been analyzed by means of finite element analysis (FEA). The reasons of the petiole’s fracture have been found through the structural static and modal simulation calculates for the axial fan’s impeller mechanical system. The structural static analysis results show that the petiole has stress concentration problems, and the modal analysis results demonstrate that the 6th-order natural frequency of the impeller system (which is 83.258 Hz) is close to 5 times of the impeller’s rotation frequency (which is 16.667*5 = 83.335 Hz), therefore it has high risk of resonance for the impeller system. So we conclude that the petiole’s fracture may greatly caused by the stress concentration and the risk of resonance, which may cause the fatigue cracks produced, and the cracks may gradually expanded and eventually caused the petiole fractured. At last, two measures to prevent the fracture of petioles were proposed.

Abstract: In galloping, reverse split wire plays an important role in. Through the study of split change sub conductor length of wire twisting motion estimation, the wire tension change caused by the torsion of sub conductors; besides considering some of the split wire torsion stiffness of the external factors, but also the influence of torsion wire tension change, caused by the conductor sag, line height worse, we deduced the general formula to calculate the new conductor spacer system torsional stiffness.

Abstract: The aim of this paper is to develop new natural fibre reinforced for automotive brake pad application. For this purpose, new brake pad sampleswere produced using Miscanthus as reinforcement ingredient. The other ingredients are Cashew, Alumina, Phenolic Resin, and Calcite. Three different laboratory formulations were prepared with varying Miscanthus fibre contents from 10, 25, and 40 (wt) and these formulations were moulded four different moulding pressure values such as 50, 100, 200, and 300 MPa. Sieve analysis, density, apparent density, and hardness properties of brake pad samples produced are examined.

Abstract: Excavated foundation has widely used in the field of transmission line engineering because of its large capacity to resist uplift and moment force. Elastic-plastic numerical model were established by using the finite element software ABAQUS focusing on the difference of bearing characteristics of inclined and vertical excavated foundation. There is very slight difference of axial uplift resistances between the both foundations because almost the same soil mass are mobilized at the same displacement loading. However, failure modes and horizontal resistances of negative, positive and vertical foundations are very different. The larger soil mass along the shaft of negative foundation is mobilized than positive and vertical foundations. The uplift resistances of vertical and negative foundations are about 5% and 25% higher than positive foundation at horizontal displacement of 50mm respectively.

Abstract: Woven composite laminates have been widely used in various application and rapidly replacing unidirectional composite laminates. Thus, it is vital to understand clearly their material parameters and characteristic. Apparently, it is very difficult to analyse the design parameters of a unidirectional composite laminate, and thus due to its weaving structure, analysing numerically the parameters of a woven composite laminate is even more difficult. Therefore, this paper aims to review the work related to woven laminates with respect to its testing and simulations. During the initial stage, a tensile test is conducted according to ASTM D3039 on the 2×2 twill weave carbon fibre woven prepeg where the material constants (E_1, E_2, G₁₂ and ν₁₂) and the deformation behaviour will be obtained. The later stage will involve the development of a finite element modelling and simulation by means of commercial finite element package ANSYS 14.0 to replicate the experimental set-up. Ultimately, the outcomes and findings between the experimental and numerical approaches will be compared and reported.

Abstract: Strain clamp is an important connection device in guy tower. If the quality of the compression splicing position is unsatisfied, strain clamp tends to be damaged which may lead to the final collapse of a guy tower as well as huge economic lost. In this paper, stress distribution on the compressible tube and guy cable is analyzed by FEM, and a large equivalent stress of guy cable is applied to the compression splicing position. During this process, a finite element model of strain clamp is established for guy cables at compression splicing position, problems of elastic-plastic and contracting are studied and the whole compressing process of compressible position is simulated. The guy cable cracks easily at the position of compressible tube’s port, the inner part of the compressible tube has a larger equivalent stress than outside.

Abstract: CFRP (Carbon Fiber Reinforced Plastics) is an anisotropic material which is the most widely adapted lightweight structural member. CFRP of the advanced composite materials as structure materials for vehicles has a widely application in lightweight structural materials of air planes, ships and automobiles because of high strength and stiffness. The CFRP Square members were made of 8ply unidirectional prepreg sheets stacked at different angles and interface numbers. Based on the collapse characteristics of CFRP member, the collapse characteristics and energy absorption capability were analyzed. The impact collapse tests were carried out for each section member. The purpose is to examine experimentally absorption behavior and strength evaluation depending on changes in the stacking configuration when the CFRP Square member s with different stacking configuration is exposed to separate impact velocity.

Abstract: To assess the structural strength of spherical cylinder, the finite element model was constructed by the NX NASTRAN software. Firstly,the basic principle of random vibration response analysis was introduced, then the random vibration response analysis of the cylinder assembly was analyzed. The simulation result shows that the stress of the joint between spherical cylinder clamp and the base is larger than other areas in conditions of a given random vibration load. The spherical cylinder structure is safe and that the maximum RMS stress is about 20 MPa.

Abstract: Incremental Dynamic Analysis (IDA) is a technique to determine the overall seismic performance of structures under varied intensities of earthquakes. In this paper, the seismic performance of four-story steel braced frames equipped with superelastic Shape Memory Alloy (SMA) braces is assessed by performing IDA. The seismic response of SMA-braced frames was compared to that of corresponding Buckling-Restrained Braced Frames (BRBFs). Based on the results of this comparative study, the SMA-braced frames were generally effective in reducing maximum interstory drifts and permanent roof deformations. In addition, the SMA-braced frames demonstrated more uniform drift distribution over the height of the building. As the intensity of earthquake excitation increases, a higher response reduction can be expected for SMA-braced frames.

Abstract: Kaedah A is a fend off technique engaged in Seni Silat Cekak Malaysia, upon confronting a punch force exerted within the vicinity of the thorax area. Hitherto, there is still lack of biomechanical analysis on the execution of Kaedah A. Therefore, this study aims at analysing the effectiveness of Kaedah A based on the total execution time as well as to describe the kinematic characteristics of the hand movement upon its execution. The experiment was carried out by means of motion capture. Microsoft Kinect was utilised to detect the hand movement whilst the post processing of the captured motion was performed via Virtual Sensei Lite. Kaedah A was executed five times by an experienced Seni Silat Cekak Malaysia practitioner to investigate the accuracy and repeatability of the system. The data obtained serves as an input for the trajectory mapping for both initial and end point identification. The time difference, Δt between the points demonstrates that the total time execution for Kaedah A is less than 0.1 s. Further analysis involves filtering the coordinate data obtained in order to generate the polynomial function of the hand movement during the execution of Kaedah A. It could be concluded that the Kaedah A execution has the features of a ballistic movement. The findings provides useful data for reliability prediction as well as further enhancement of the Kaedah A itself.