Applied Mechanics and Materials Vols. 182-183

Abstract: In order to improve the absolute accuracy of the robot, one new simple and inexpensive, yet accurate robot calibration method is presented. The process assumes the robot can move along a line in the robot’s workspace. The actuators remember the angle information of each joint, when the robot moves along the line. The date that obtained by this method, simplify the process of deducing the kinematic parameters. The paper establishes the evaluation function, which demonstrates the fitness degree of the robot’s position and orientation to the line. In the end, simulation method has been adopted to testify the method, and the method is shown simple and feasible.

Abstract: The paper is aim to investigate the interaction of a screw dislocation in strained reinforcement with a lip-shaped crack under remote longitudinal shear load using complex variable method of Elasticity. The exact solution of complex function of the matrix and the renforcement layer are obtain in series form; then, the expressions of stress field, image force and stress intensity factor of crack tip can be derived; finally, numerical disccusions are pesented and the results shows that the lip-shaped crack in reinforcement layer has interference effect on the interaction of dislocation and reinforcement layer, and the eigenstrain in x-direction has little effect on image force; however, the eigenstrain in y-direction has great influence on image force.

Abstract: In this paper, SEM, EPMA, and micro shear experimental method were applied to analyse the structure, inclusion morphology and composition, micro-area strength and toughness of the X70 pipeline steel girth weld joint. The results show that inclusions are mainly nonmetallic oxides, sulfides and calcium compounds. The length of inclusions can be up to 1mm, which have substantially reduced the strength and toughness of weld joint. By the combining effect of internal and external force, cracks tend to initiate around inclusions and propagate along the direction of inclusions, and finally reduce the impact toughness of girth weld.

Abstract: Basing on confirming the structure parameters of relative components and simulation, movements of material on the sieve were analyzed, and then put forward one new-style structure of sieve. According to every point’s k_v and movement locus on the sieve, figure equation of whole sieve was found. The optimal figure of sieve which is fit for the filtration and transportation was acquired. Through analysis and computation, material’s transportation velocity was achieved, and checked out the material transportation efficiency furthermore.

Abstract: In this paper, the finite element method of rectangle nested refinement was introduced, and the level Κ rectangle grid refinement and related properties on planar region were given. According to boundary problems of a kind of elliptic equation, the results of the convergence were proved for the finite element of Κ level rectangle nested refinement under Q₁ mappings by affine mappings replaced.

Abstract: In this paper, the weighed error estimation of finite element method for the two-point boundary value problems are discussed. Respectively, the norm estimation of the H¹ and L² are obtained.

Abstract: The certain nitrate ester explosive has been tested by TG at the heating rates of 10, 15, 20, 25K•min^-1. Basing on the TG experiment results the thermal decomposition activation energy has been calculated by the methods of Ozawa, KAS and iteration. And the thermal decomposition mechanism function of the explosive with 38 kinds of dynamic function was deduced by the method of integration. The results show that the thermal decomposition mechanism of the nitrate ester is chemical reaction mechanism. The thermal decomposition kinetic parameters such as average activation energy E_a and pre-exponential factor A are 133.23×10³ J•mol^-1 and 3.191×107 s^-1 respectively.

Abstract: In this paper, the elastic plastic damage model for concrete under static loading previously proposed by Hu Qi et al. is developed in ABAQUS via UMAT, and it is verified by the simulation of two shear wall members under horizontal loading. The simulation results indicate that this constitutive model can accurately predict typical nonlinear performances of reinforcement concrete shear walls. Using the proposed model one can get the damage distribution of reinforced concrete members which is helpful for researchers to get the failure pattern of structures.

Abstract: Wear is the matrix surface and plastic deformation as the basic factors of the phenomenon, this paper analyzed with abaqus finite element method friction deformation which stress. The results show that the stress state changes drastically with different friction coefficient and the distribution of plastic deformation regions also changes. The regions seriously damaged by friction lead to fatigue via plastic deformation, which is the main reason for material friction and then dislocation friction occurs.

Abstract: This paper constructs the planar dynamic systems with non-equidistant cyclic windows. To generate planar tiling images with different visual effects by the same iterative mapping, we propose a method that allows the planar tessellations to be constructed by a planar dynamic system with non-equidistant cyclic windows. A family of iterative mappings are constructed which generate cyclic windows of variant size in the dynamic plane by incorporating cosine functions and non-linear angle variables with the same parameters. Filled-in Julia sets in different cyclic windows are created by generating the coordinates of any cyclic windows. The images in different windows are continuous but with individual structures. We can choose any cyclic windows as the basic computing region and stretch or compress it into a square, which is transferred to the plane to compose the planar tilling. Experimental results show the effectiveness of the proposed approach.