Applied Mechanics and Materials Vols. 670-671

Abstract: The Skewed–Roller Slipping Clutch (SRSC) produces resistant torque which depends on the relative rotation and sliding between askew arranged cylindrical rollers and specially curved races. In this paper, the surface contact stress and von Mises stress distributions between the dub-off profiled rollers and races are calculated, with consideration given to the frictional contact and dynamic equilibrium of the rollers. The effects of the profiled roller’s parameters on the von Mises stress are investigated and the optimal modification parameters are calculated. In addition, the limiting resistant torque characteristics of the slipping clutch with optimal profiled rollers are discussed in detail.

Abstract: The method of planar four-bar mechanism movement precision analysis is proposed when the length errors and kinematical pair clearances are taken into account. The offset vector caused by the clearance of kinematical pair is analyzed and the position vector is used to describe the position of bodies. The structure for the two-hole swing deputy is studied. The magnitude and direction of rotary vice offset is seen as random variable. The calculating formula of two-hole effective lever length model is deduced. The output accuracy of four-bar mechanism with two-hole the clearance is analyzed.

Abstract: This work consist to make a dynamic study of an actual structure sized before applying Moroccan seismic regulations RPS2000, the study will be made using the SAP2000 software and exploiting accelerograms of Al Hoceima’s earthquake occurred on 24^th February 2004, this earthquake was recorded at several Spanish stations this analysis will first identify some dynamic characteristics of the studied frame like eigenmodes of the frame and the maximum displacement of the terrace. The use of several accelerograms will highlight the influence of distance on the intensity of the earthquake and will give some information about sol-structure interaction

Abstract: Move performance in six-degree-of-freedom is one of the important indexes of hydro-dynamic property of tension leg platform (TLP). This paper discusses the time domain dynamic response characteristics of a tension leg platform in the regular wave. The paper focuses on the effects of the incident wave angles (15 °, 22.5 ° and 45 °), the wave height (6m, 8m and 10m) and the wave period (10s, 12s and 14s) on the movement of tension leg platform, the top tension of the tension leg. The results show that: because of the different sensitivity of the tension leg platform to the incident wave angle, the wave height and the wave period, the motion characteristics is different.

Abstract: The settling velocity of sediment is a hot issue and a basic problem in study of sediment transport and estuarine engineering. According to field hydrodynamics and sediment data around the South Passage of the Changjiang River in China, this paper detected the characteristics of sediment particle size and vertical distribution pattern of suspended sediment concentration, and further estimated the settling velocity of suspended sediment in three methods. The results show that the sediments including suspended and bed load can be categorized into cohesive sediments and the sediment concentration profile agree well with logarithmic distribution. Furthermore, by comparison, it is found that the Rouse formula is more reasonable for estimating the settling velocity of fine sediment, but the Zhang Ruijin and Stokes formula obviously underestimate the values of settling velocity, caused by do not taking into account the flocculation of fine sediment in estuary.

Abstract: With the popularization of computer, the design of planetary gear trains is headed in the automatic direction. Based on the theoretical research of closed differential planetary gear transmission mechanism, a kind of software was developed to automatically calculate the tooth number with computer technology applied to the design of gear trains. Some research and analysis were done to the transmission mode of closed differential planetary gear transmission mechanism with the help of universal design method on gear trains. Five constraint conditions were summarized, which are gear ratio condition, adjacency condition, assembly condition, concentricity condition, and other conditions, and a optimum condition. With windows 7 as the platform, MyEclipse 8.5 as a tool, translating these conditional formulae into Java language, the software of the selection of tooth number for closed differential planetary gear transmission mechanism was developed. Multi-group datum of tooth number and also a set of optimal data can be obtained after running the software, which reduces the workload of manual calculation.

Abstract: In the situation that energy is increasingly grim, how to use high-sulfur fuel effectively and reasonably is a big problem for high-energy consumption cement industry. But high-sulfur fuel will also brought up crusting problem because of higher concentration of circulating and accumulating volatile components. By-pass system can resolve this problem. Rapid-cooling mixer is key equipment for by-pass system. The thermal flow field inside the mixer determines the performance of rapid-cooling mixer directly. CFD method is used to simulate the flow field and temperature field inside mixer. The simulation result help to guide and test the improvement of mixer structure design. After optimization structure design, the mixing of hot gas and cooling air is full and strong inside mixer that leads to excellent cooling effect and good protection for equipment from crusting.

Abstract: The traditional method of finite element that fixing constraint between suspension and chassis for the damaged aircraft recovery trailer chassis usually ignored the buffer function of suspension leading to too much stress, So aiming at that problem The constraint of trailer is fixed by the method of balance frame system. Based on FE-software ANSYS the FE module of trailer chassis and balance frame system is set up and their node is coupled by the force analysis of aircraft with half of fuel in damaged. It's result that the maximum stress is less than permissible stress.The result show that the method of balance frame system is more practical by computer simulation.

Abstract: A lightweight sandwich composite armours has been established by comparing the ballistic resistance of the potential component materials. The ballistic-resistance properties of the armours under impacting by the bullet with 12.7mm diameter are also numerically investigated by using finite element software LS-DYNA. Numerical modeling is used to obtain an estimate for the ballistic limit velocity (V₅₀) and simulate penetration processes. The focus is placed on the energy absorption capabilities of different component layers with same density per unit area. The influence of stacking sequence and thickness ratio of ceramic/fiber layer has been analyzed in detail. Results indicate that the composite armour having optimal thickness ratio of ceramic/fiber layer in the same density and its mass is 29% lighter than of 4340 steel target.

Abstract: In order to solve the problem of seedling damaged and inefficiency of pot seedling trasplanter, the manipulator for pot seedling transplanter came into being. The three thin finger structure was selected for the manipulator, which could weaken the resistance and leakage by employing pneumatic drive. SolidWorks software was used to establish the 3D model and virtual assembly, to analyze force on the finger on the basis of the mechanical design theory. The strength of the finger part was checked in the SolidWorks SimulationXpress module, the maximum pressure of the finger was 50040656 N/m², which was far less than the yield strength of the alloy steel finger 620422016N/m². The results showed that the manipulator was highly practical with reasonable structure and productivity-enhancing ability.