Advanced Materials Research Vols. 189-193

Abstract: Granite is a kind of high damping material with low thermal expansion, so it is widely used in aerostatic guideways. However, moisture expansion may occur when the granite works in a moist environment, so the applicability of granite to oil hydrostatic guideways is investigated in this paper. By error modeling for a typical closed hydrostatic guideway with four pads, it is shown that the motion errors are mainly determined by geometric errors of the rails when film stiffness of each pads are equal. Experiments on rails of Jinan Dark Green granite are carried out, and the results show the rail straightness variation by the moisture expansion may be less than 1μm/300mm. According to the previous analysis on the error averaging mechanism of hydrostatic guideways, the motion straightness variation may be less than 0.1μm/300mm. In addition, the thickness variation may be less than one ten-thousandth of the rail thickness and the viscosity of liquid has little influence on the moisture expansion.

Abstract: A novel copolymer of poly(acrylamide-co-acrylamido azobenzene) consisting of acrylamide (AAm) and acrylamido azobenzene (AAAB) was synthesized via a free-radical polymerization route by using 2,2’-azobisisobutyronitrile (AIBN) as initiator. The investigation of UV spectra of the copolymer aqueous solution that exposed to UV irradiation revealed that p(AAm-co-AAAB) possessed good UV photoresponsive properties. The photoresponsibility was proposed to stem from reversible transformation between cis and trans isomers of azobenzene groups in the side chains. The concentration and molar ratio of copolymer have some influence on the photoresponsive behaviors.

Abstract: The purpose of modelling the processes of compression and thermal softening of particulate, as well as porous and anisotropic materials is to determine the critical stress condition which initiates plastic flow of the material. This value is critical for the effectiveness of thermal softening process and depends on the thermo-mechanical parameters of the material and the key parameters of the process itself [2,4]. As it has been proven by research, the strength of materials such as wood and sawdust evidently decreases with the increase of temperature, influenced also by the moisture content of the material. For determining the distribution of temperature in a layer of thermally softened material it is indispensable to determine the heat transfer coefficient. This paper presents a test fixture for measuring heat conduction in natural composites materials, allowing for the effect of temperature, developed by the author.

Abstract: The work treats about problem of designing of gear with timing belt depending on expected character of exploitation. The work presents constructional features of transmission timing belts depending on materials used for their production. Design of composites and usage of new polymer materials allows for improvement of constructional properties of belts.

Abstract: When sequential compliance method is used for Weibull distributions, the shape parameter is usually considered to be fixed. However, because of the life of products are determined by many factors, the shape parameter is variational in practice, that is to say, the shape parameter in the criterions is different from that in the practice. In this paper, the changes of acceptance and rejection probability are researched by the influence of shape parameter changes. Finally, by means of simulation test, changes on the shape parameter affecting on the probability of acceptance and rejection are quantitatively analyzed. As a result, the larger the gap on the shape parameter in the criterions and in the practice is, the larger the gap on the producer’s risk and the consumer’s risk.

Abstract: Concrete frame structure in epicenter region has greatly damaged by Wenchuan Earthquake, especially short columns. Plenty of means for reinforcing these structures have been used. Finite element software ANSYS is used to simulate mechanical properties of structures after reinforced by broaden-section under monotonic or cyclic load. Comparison of frame’s horizontal displacement, crack of bearing carrier and distribution of node’s shearing stress etc. before and after reinforcing, it proves that broaden-section method is feasible in reinforcing of frame structure. Most of all, it verifies that broaden-section method has better reliability on reinforcing of RC frame’s short column.

Abstract: The epoxy resin concrete is one of high performance composite materials used to the basic parts of machine tool and measuring instruments. Based on the study of related technologies at home and abroad, technical route and manufacturing process on the development of machine tool bed have been proposed. The epoxy resin concrete material self developed and results of its performances testing are introduced, and they are contrasted with cast iron material. The high-speed CNC lathe was taken as example which characteristic of the epoxy resin concrete bed structural design has been explained in this paper. The cast iron bed and epoxy resin concrete bed of the high-speed CNC lathe has respectively been analyzed and contrasted by finite element method. At last, the performances of epoxy resin concrete bed exceeding to cast iron bed have been educed.

Abstract: The cermets were prepared for aluminum electrolysis as inert anode. The microstructure of cermets inter anode was dense , the crystal of cermets growth ideally. The electric conductivity was stable and good, had the electric conductivity property of the semiconductor. The conductivity increased with temperature increasing. Electrolysis was conducted 12h at 850°C in cryolite molten salt(CR=2.0, Al₂O₃ comtent 5.0% ), and the anodic current density was 1.0 A/cm2.The results showed that the cermets inert anode had high anti-oxidation, corrosion resistance and high conductivity. The back electromotive force was 2.45V, the decomposition voltage was 2.18V, the conductivity at 850°C was 47S/cm, the annual corrosion rate was 23.68 mm/year.

Abstract: Creep fracture mechanics parameter C* is used to relate the data of Creep crack initiation (CCI) and Creep crack growth (CCG). Reference stress method (RSM) can be used to explain the result of finite element analysis on evaluating structures, and it is widely used to design and assess of general structures. The result of C* is affected by the creep coefficient A and creep exponent n for power-law creep in solving creep fracture mechanics parameter C* though using RSM.

Abstract: Iron tailings is the bulk waste produced by steel plants that has not yet been used. In this study, the mineral composition of iron tailings was determined by XRD. The microstructure was observed by SEM-BEI. Resin-based composite materials with different contents of iron tailings were prepared by compression molding method and the tribological properties of the composites were studied. The results showed that: when the contents of iron tailings were 10%, 20%, 30%, 40% and 50%, the friction and wear properties of the resin-based composite materials can meet the standards for automotive clutch (GB/T 5764-1998). Among these samples, the sample with 20% iron tailings had the best performance. This paper provides a new way for the use of iron tailings.