Applied Mechanics and Materials Vols. 101-102

Abstract: The principle of the multilayer gridding algorithm, as well as its applications to the numerical calculation of water lubricated plastic alloy bearing elastohydrodynamic lubrication (EHL), was described. The computation of water lubricated plastic alloy bearing EHL was carried out by the numerical model based on the linear contact theory. A cuneiform water film on the frictional surface between bearing and spindle is formed because the plastic alloy has a high elasticity and low elastic modulus, which lead the water lubricated bearing easy to be distorted.

Abstract: The functions of the tool radius compensation in the NC processing are discussed. The functions mainly include: simplifying programming; fitting the changes of the tool; simplifying the finish machining; controlling the accuracy of the contour; machining the parting surface coupled with the concave and the convex. Some notices that must be observed strictly are also discussed.

Abstract: Based on the principle of the dimension chain, this paper studies the dimension chain mathematical model and chooses a reasonable method for calculation of the dimension chain, establishing a model of the calculation of dimension chain margin of computer aided analysis and calculation. On AutoCAD platform, we developed the dimension chain calculation analysis software through secondary development by VBA, and applied the technology to dimension chain margin check. This significant saves the time spent in the process of manually calculating the dimension chain.

Abstract: The arm is a key component of the humanoid massage robot system. On the basis of in-depth study on massage working mechanism of robot arm, a three dimensional parametric model is structured using SolidWorks. Through data conversion technology, the model is imported into ADAMS, and follow-up constraints and loads are added, with which the kinematics analysis on shoulder, upper arm and wrist joint are completed. It lays a solid foundation for the in-depth study on robot arm of massage working mechanism and the practical application. It can realize the prediction of the massage arm performance on the design phase, simplify the design process and shorten the cycle of the design as well as improve the design quality.

Abstract: The connecting rod is an important part in the engine cylinder. This paper studied the engine cylinder by using Pro/E and ANSYS and achieved some interest results. It used the Pro/E to establish three-dimensional model of the engine and to simulate on it. It also analyzes the connecting rod of cylinder by using the finite element analysis software ANSYS, its modal analysis method was put forward and the low natural frequency and vibration mode were calculated. The analysis method and the results can provide reference for the dynamic design of the connecting rod, and also provide a method for the fault diagnosis engine system.

Abstract: A simple method based on the well-known sectional analysis approach is presented to trace the structural behavior of reinforced concrete (RC) shear walls exposed to fire. It is similar to the approaches described in the existing literature but it does not require computations of moment-curvature curve group. This method can take into account material nonlinearity by use of the coupling constitutive relation of materials. Moreover, the geometric nonlinearity is considered by taking account the second-order effect of axial forces. The predictions of the proposed method are validated using experimental and analytical studies.

Abstract: An intelligent classification system of ceramic tiles is introduced in the light of the theory about multi-sensor information fusion. The system includes image acquisition, image processing and intelligent classification of ceramic tiles. The color features and shape features of tile image are synthetically processed using BP neural network. The topological structure of the neural network based on “681” structure is proposed in the system. The numerical calculation and simulation about classification of ceramic tiles is carried out based on MATLAB software. The results show this algorithm is fast and accurate, which can effectively accomplish the classification of comprehensive detection of ceramic tiles.

Abstract: In this paper, an effective optimization and decision making method was proposed to deal with the multiple attribute decision making problems in technology design of coal mine refuge chamber. It is more reasonable that both attributes’ subject weights assessed by experts (DMs) and intrinsic weights inside the alternatives are taken into account. The main factors, which affected DMs’ decision making, were analyzed and subdivided to 14 elements, and then a MADM model for chamber design was introduced subsequently. A case was studied to demonstrate the application of the model, and the results show that the chamber’s capability of withstanding overpressure, temperature control, flexibility and investment cost are crucial elements which are connected with the product’s superiority and should be paid more attention in technology design.

Abstract: This paper introduces the detection and evaluation results of a diseased highway bridge using nondestructive testing method according to Chinese specification. The bridge was firstly inspected to judge the apparent diseases of deck pavement and upper stuructures. The end-span prestressed concrete hollow slabs were detected by nondestructive testing for rebound strength and carbonation depth of concrete, corrosion and concrete cover of prestressed bars and cracks at bottom surface of the slabs. The synthetic judgement is given out based on the inspecting and testing results. Some measures are proposed for strengthening the bridge such as bonding steel plates and carbon fiber reinforced polymer laminates on the bottom surface of diseased slabs, recasting concrete of slab joints and renewing asphalt concrete of deck pavement.

Abstract: Combined with a freeway widening project, an old bridge composed by simply supported prestressed concrete hollow slabs in 20m span was detected in-site for deciding whether it can be further used, which was designed according to the former design code. The maximum test load was calculated under the worst load combination at service stage according to the current design code. The inspection of the bridge was conducted by nondestructive testing methods for strength and carbonation of concrete, concrete cover and corrosion of prestressed strands. The service behaviors such as crack and mid-span deflection of a slab were measured by static loading test. The entirety of the bridge was detected by dynamic loading test. The results show that the strength of concrete and the concrete cover of prestressed strands meet with the design requirement, the carbonation of concrete and corrosion of prestressed strands is insignificant, the bridge is in good service performance, and the slab has enough flexural stiffness to prevent larger deflection.