Applied Mechanics and Materials Vols. 37-38

Abstract: The experimentation modal analysis is made in the bed of the CNC machine tool with the hammering method of the pulse excitation. Then the dynamic characteristics of this bed are studied and the natural frequency of the bed in the specified frequency band. It supplies a clear reference for the structured optimum design of the bed through the analysis of the main mode on every rank.

Abstract: Bed is a main component of a large precision linear rolling guide CNC grinding machine tool Its dynamic characteristics impact on machine tool’s machining precision and stability directly. In this paper, boundary conditions on the bed of a machine tool factory’s production are analyzed. By using FEA method, the bed finite element models for dynamic analysis model are established and calculated. It provides guidance in investigating the effect factors of machining precision, the machine tool’s structure optimization and error compensation.

Abstract: The linear rolling guideway is one of the most essential parts of the machine tool. So it is very important to analyze the dynamic-static characteristic of the machine tool by considering rolling guideway for the study of the effect on machinery function. The research is based on a NC machine tool produced by a certain plant of machine tools. In this study, methods of simulating the rolling guideway support were studied; and the configuration of the spring damper elements of the bearing supports were investigated. The finite element analysis on the CKS6125 machine tool was used to confirm its dynamic characteristics. The finite element analysis models were validated by some experiments.

Abstract: Flexible assembling fixture (FAF) is a new-style assembling equipment in assembly process of aircraft panel components, which is developed based on combination of digitization of assembling and automated modular fixture. The multi-actuator is designed to positioning and clamping the panel component. The dynamic behavior of the FAF is analyzed in process of 3D structure design. The motion and displacement of every actuator are analyzed based on kinematic and dynamic theory, by means of building the Knopoff model taking friction between the vice sport into account. ADAMS is employed to carry out the dynamic simulation. This technical approach is the effective solution for developing the new equipment; moreover, its result presents a great engineering significance in improving the equipment performance.

Abstract: By using a new type pure rolling fatigue test rig with three contact points for silicon nitride bearing ball specimen, the contact deflection angle of specimen with three contact points is calculated. The effects of the center height and test ball radius on the specimen contact deflection angle are analyzed. The analysis indicates that the span of contact deflection angle is 0-0.181° while the center height is 1.2mm and the design radius is 6.35mm and the specimen radiuses change from 4mm to 8mm. The more contact deflection angle is, the more variation rang of test ball radius is. The contact deflection angle can be less than 0.2° while the center height is optimized. The contact deflection angle has a direct influence on the stress error of the specimen. It is less than 1% while the contact deflection angle is less than 0.2°. The research provides a theoretical basis for optimization of test rig structure size and increase of specimen’s extension and improvement of test precision.

Abstract: The nickel coatings and electroplated diamond tools were fabricated with ultrasonic and without ultrasonic condition. Hardness and adhesive strength of nickel coatings were tested. Diamond grains on tool substrate were observed with microscope. Al2O3 ceramic was machined with fabricated electroplated diamond tools to compare material removal rate and grinding ratio. Experimental results show that high hardness can be obtained under the effect of ultrasonic during tool fabrication processes. Ultrasonic agitation can make grain dense and guarantee nice contact between substrate and coating. With ultrasonic power of 200W, nickel coating presents highest values of hardness and adhesive strength. High grain density of diamond tool can be obtained. During buildup processes, some buildup time is needed to obtain enough thickness of nickel coating before ultrasonic agitation is applied. Grinding ratios of diamond tool with ultrasonic during buildup processes were better than without ultrasonic. The diamond tool fabricated with ultrasonic agitation presents better cutting ability. During tool fabricating processes, the reasonable application of ultrasonic agitation is very important.

Abstract: Grinding stability was analyzed concerned with contact deformation and contact stiffness of wheels. Elastic deformations of the grinding wheel were measured with inductance sensors. Dynamic grinding system model was set up. Relation between contact stiffness and chatter growing index was analyzed. Chatter suppression experiments with variable grinding speeds were carried out. When wheel is in contact with a workpiece, contact deformation can occur. The contact stiffness of grinding wheel is a variable. The relation between chatter growing index and contact stiffness is an increasing function. Chatter growing index can be decreased by lowering contact stiffness of wheel. The grinding system stability will be improved with variable grinding speed.

Abstract: For machining of hard and brittle materials, iron electrodeposit is a kind of matrix material with potential advantages for manufacture of diamond tools. Aiming at the problem of difficult codeposition of diamond in iron deposit, this paper adopts orthogonal design of experiment to study the effects of solution pH value, cathodic current density, alkylphenol polyoxyethylene (10) ether (OP-10) concentration and ammonium chloride concentration on codeposition of diamond, and then Fe-based diamond bits were fabricated and drilling tests in granite were carried out. The results show that pH value, cathodic current density, OP-10 concentration and ammonium chloride concentration all have statistically significant effect on codeposition of diamond in iron deposit, whose contributions to the variance of the weight of codeposited diamond are 37.45%, 32.05%, 13.13% and 12.38%, respectively. The result of drilling test indicates that Fe-based diamond bit can achieve much higher penetration rate than common Ni-based diamond bit.

Abstract: Starting from the product life cycle, this paper established the modeling of enterprise cluster entity at the base of analyzing the various products of the enterprise cluster. The modeling comprises the process dimension, resource dimension and organization dimension. Every dimension was expressed by the analysis of product view. Then, based on the complex network theory, we obtained the distribution of the products by the product network. Finally, we got the relationship of enterprise cluster entity from the result of the product network.

Abstract: The fundamental purpose of housing design innovation is to provide residents with functional, well equipped, comfortable and beautiful living space, to achieve sustainable development goals of saving land, energy, materials. In order to set reasonable targets and standards for evaluation, we adopt a comprehensive fuzzy method to evaluate and compare the program overall performances, on the base of collecting the tenements views on the performance, price, use effect as well as various technical and economic indicators of residential building system of the new technology and new materials of the housing construction, soliciting for the advice of Designers and Construction workers, considering the factors of technical, economic and social, combined with our experience.