Advanced Materials Research Vols. 479-481

Abstract: A low cost shock absorber easy to install and tune was designed to solve the vibration problem produced by the compressor in chemical process. By establishing the mathematical model of the dynamic shock absorption, the shock absorber characteristics were analyzed theoretically. The preliminary experiment was conducted on the testing platform to simulate the factory conditions. The shock absorber was then installed on the compressor for the field validation. Testing results agree well with theory and the shock absorber showed good damping performance.

Abstract: In order to solve the continual bolt fracture fault for gearbox of rolling mill in one cold strip rolling mill plant, vibration signals of gearbox in the process of rolling were collected by experimental research. Based on the signal analysis, combined with the results of statics and modal analysis of bolt, abnormal vibration of gearbox is confirmed the main cause for bolt fracture. Moreover, by further signals analysis of gearbox and vibration intensity analysis of bearing pedestal, finally found deflection of input shaft is the direct cause for gearbox abnormal vibration. Through the maintenance, it was found that eccentricity ring of bearing of input shaft had been worn down. The results of maintenance proved effectiveness of this paper.

Abstract: The stability of the controller based on traditional adaptive active noise control(AANC) adaptive algorithms is not sufficient because of the time-varying parameters and essential nonlinear property of the active noise control system. The results show that the performance of the controller using multi-channel dynamic neural network algorithm which possess favorable silencing effect and stability is superior to the one using AANC.

Abstract: The paper starts from the reasons of the Centrifugal Compressor’s oil-film oscillation in one factory of Longyan, and thinks oil-film oscillation is the typical one of faults of the high-speed glide bearing and happens at about two times of the critical speed. It also summarizes the features of the oil-film oscillation, analyzes the reason, and finds out that the problem is related to the load, critical speed, the relative eccentricity of the bearing, lubricating oil and the bearing’s load amount. Finally it puts forward HHT detecting methods which can accurately find the problem earlier, and proposes improvement measures which have been proved simple, convenient, and practical after half year’s experiment.

Abstract: Internal friction behavior of a porous CuAlMn shape memory alloy was examined. Two internal friction peaks appear at around 350 oC and 380 oC during the first heating process in the as-quenched specimen, but they disappear during the second or more heating process. Two other internal friction peaks are found at around 150 oC and 325 oC from the second heating process. Correlated mechanisms of the peaks are discussed.

Abstract: The performance of particle damper is highly nonlinear whose energy dissipation is derived from a combination of mechanisms including plastic collisions, friction, and momentum transfer between particles. Particle damper can be applied in extreme temperature environments. In this paper, an investigation on particle damper is performed analytically and experimentally. A simulation algorithm and results of simulative studies aimed at understanding the effects of parameters of particle damper are presented. Parameters considered include damper geometry, particle material and particle size.

Abstract: The powerful propulsion system of vessels with double engines and double propellers is commonly used for harbor utility crafts, offshore platform supply vessels and etc.. Their shafting torsional vibration evaluation methods differ from those of one-engine vessels, so it is necessary to use appropriate methods to get scientific evaluation results of the two kinds of shafting. For vessels with double engines and double propellers, the shafting torsional vibration is calculated theoretically by specialized calculation software; a practical scheme is designed and put into use to the real ship testing. The torsional vibration test data of four sets of propulsion shafting of two ships were collected and analyzed. The preliminary results drawn from the analysis can provide references for ship shafting torsional vibration test and analysis.

Abstract: In this paper, methods of acquiring internal loss factors and coupling loss factors by experimental measurement are investigated. The internal loss factor and coupling loss factor of two coupled plates is measured by the modified power injection method. The SEA model of coupled system is established based on the measured results of internal loss factor (ILF) and coupling loss factor (CLF). A random vibration analysis is conducted as a validation example. Since the formulation solution and measured result agree preferably, the validity of the measurement method and the effectiveness of analyzing vibration response using SEA are proved.

Abstract: The contradiction between the effective supply and the uncertain demand in housing security system, which is an important part of the urban social security system, has been a major obstacle to urban sustainable development since 1998, and how to effectively deal with it is becoming more and more important. In this paper, the uncertain demand of indemnificatory housing, which was caused by the rapid urbanization, is considered, and the models for indemnificatory housing provision under box constraints, ellipsoid constraints and polyhedral constraints are constructed respectively by using distributional robust optimization, and at the same time, the reliability of optimal models in theory is proved in the form of theorem. In the end, as application of models, the paper takes Beijing as an example, and conducts empirical research on provision of indemnificatory housing during the past five years (2006-2010), which shows the effectiveness of the method.

Abstract: Abstract:The dynamic characteristics of CY6140BT lathe were studied using the GLOBAL method. The damping rations and modal shapes of the main modal frequencies have been obtained. Correctness and reliability of the model were verified by comparative fitting results method. The results show that the working frequency fended off natural frequencies of the lathe. Which indicated that the lathe meets the design goals and work requirements.