Applied Mechanics and Materials Vols. 184-185

Abstract: In order to analyze the ogive effects PELE broken Finite-Thickness reinforced concrete (RC) targets, a variety of shape and materials ogive for PELE penetration 24 millimeters RC targets was analyzed using numerical simulation by LS-DYNA 3D finite element analysis software, the simulation results show that the PELE projectiles with a hollow cone shape and phenolic resin material ogive have better effect of broken RC. And the simulation model for the real experiment, the test results and simulation results agreed well, the simulation calculation model and parameters for PELE is credible, which can provide useful reference for design.

Abstract: In order to increase the accuracy of the experienments of sugarcane’s physical cutting indoor. Due to the practicality of the ingathering by machines in field, the group did some simulation design of clamp holder for sugarcane’s structure on the experienment table. As to make sure the cases in laboratory are close to those in the fields, inflict suitable force to the sugarcane. The parameters of the two kinds of soil including the water content and the hardness value of soil are different. The dry one is 8.7% and 17.5kg/cm2. The wet one is 19.05% and 6.83kg/cm2. The structure of clamp for sugarcane is the form of two springs. 65Mn as material, the diameter is 3 mm, the free length is 130 mm, the active length is 127 mm, the stiffness coefficient is 44.3N/mm.

Abstract: Based on the importance and complex working environment of hydraulic support, welding residual stress (WRS) measurement to main components were carried out respectively by X-ray diffraction and the measured data were further analyzed theoretically. Tests were made on the gob shield and base for two times, each was measured before and after heat treatment respectively. The results indicate that WRS in the base are higher than that in the gob shield before heat treatment. After heat treatment, residual stress (RS) level of gob shield and base decreased significantly, WRS in every region keep at a lower level and regional RS differences become smaller. Therefore, heat treatment processes is an effective method to reduce RS of hydraulic support after welding. Through the test results we measured, got the real residual stress level of gob shield and base, which can provide the basis of experiment to search for an appropriate welding and heat treatment process.

Abstract: Gunpowder composite welding rod is a new type of welding material, which is mainly composed with gunpowder and thermite. This welding rod has the following characteristics: (1) portable welding rod; (2) simple and safe in operation; (3) high controllability of combustion; (4) don’t need outside energy source, et al. obviously, all characteristics indicate that this welding material can satisfy the demand of field emergency or civil device emergency. In this article, the mainly components and characteristics of gunpowder composite welding rod are introduced in detail.

Abstract: Abstract. Embedded K nickel chrome-nickel silicon thermocouple was used to measure the grinding temperature of stainless steel in the cases of high-speed grinding while machining SUS304 Stainless Steel with vitrified CBN wheels in high speed grinding conditions.The energy partition is approximately 7.7% by matching the measured temperature to the analytically computed temperature. 3D FEM simulations for some typical grinding conditions are carried out.The error between the simulation analysis temperature results and the experimental results is approximately 3% on the grinding surface,and the error between the simulation analysis temperature results and the experimental results is approximately 10% below the grinding surface.

Abstract: The definition and research background of friction is introduced. The reason of generation of friction is analyzed, the importance of the coefficient of friction test in sheet metal forming field is indicated. The testing principle of coefficient of friction on metallic sheet is presented. The basic data processing method of the test is described. Two important data processing techniques which will obviously effects the test results, including effective friction zone and normal pressure have been carefully studied. The comparison result shows these techniques can effectively enhance the testing stability and precision.

Abstract: Nonmetallic material by stress which less the yield stresses long time, it would force creep. Nonmetallic materials’ operating life depended on the creep degree. The paper set up creep model using ANSYS, create the nonmetallic material creep strain-time curve, got the creep properties of nonmetallic material. To provide effective basis of calculate the nonmetal materials’ operating life.

Abstract: This paper gives the influence of the coarse aggregate size on the mechanical properties of the beam with different coarse aggregate sizes under static loads. In the research, three reinforced concrete beams with three different coarse aggregate sizes separately are tested. The stains and the deflections of the beams under the static loads are measured. The results show that under the action of the same loads, the maximum strains of the reinforced concrete beams with the big and the small aggregate size separately are larger than that of the beam with mixed aggregate size, and the deflection of the beam with the big aggregate size is larger than that of the beam with small aggregate size. In the loading process, the changes of the normal section strain of the reinforced concrete beams are satisfied the assumption of the plane section.

Abstract: In order to determine the fatigue limits of two kinds of titanium alloy pipes connected by welding and rolling, fatigue tests were carried out by the Aero-Criterion which gives vibration fatigue test method and failure criteria. A laser-displacement-sensor was used at the free end and a strain-gauge at the root of the pipe specimen. The test result shows that the fatigue limit of the welded pipe is higher than the rolled one. In the end some new findings are listed according to the test.

Abstract: A novel design of lower limb rehabilitation robot was developed for lower limb dysfunction, such as stroke, paraplegia, traumatic brain injury and so on. Through analysis of clinical applicability, the design makes some improvements from material, structure, operation means and control system. In this paper, the spring device and magnesium alloy exoskeletons were introduced carefully, which can adapt changes of human gravity centre as walking and lighten the weight of wear. All of above are important for the clinical applicability of the robot.