Applied Mechanics and Materials Vols. 26-28

Abstract: The conservation of historic stone sculptures and buildings is receiving growing attention because of increasing bad weathering. In this paper, we report our experiments on the conservation of the Longmen Grottoes through a biomimetic method. Some relevant experiments have been done in the lab at first. A protective film of calcium oxalate has been prepared on the marble stone through a biomimetic synthesis. The obtained material was characterized by XRD and SEM. The protective performances were also evaluated by its ability to resist soil and acid. Then, the field trials have been carried out in Longmen Grottoes. The results obtained from the laboratory experiments and field trials are satisfied, which indicates that the conservation of historic stone sculptures and buildings through the biomimetic method should have a good prospect.

Abstract: According to the analysis of every feature element’s grey images in RGB color space and HSI color space, each of the elements represents different information of the color image. From the analysis of the Histogram of color images, the value range of hue H basically keeps stable, which is proved by experiments to be the most stable and representative one. Finally we illustrated by application instances that the method of recognition and tracking of the objective moving robot based on hue character H is applicable.

Abstract: This paper tries to find the ways to improve the service quality which government supply for business and public and improve service satisfaction. In order to find the methods, the paper firstly introduce the conception of Government Customer Relationship Management, then analysis the relationship of Customer Relationship Management and Government Customer Relationship Management, build e-government application model of Government Customer Relationship Management, propose the ways of e-government application of Government Customer Relationship Management, through establish the service concept of “citizen-centered", innovation and integration of communication and service channels, we can improve the relations of customer and government, improve the public satisfaction.

Abstract: Selective Laser Sintering could manufacture high complex metal parts in short time but with high porosity and low strength. The components from Cold Isostatic Pressing have excellent performance with uniform organizational structure, high size precision, and high density. It, however, could not form high complex parts because of the difficulties of bag manufacture. So it will be a good method to combine Selective Laser Sintering and Cold Isostatic Pressing to make complicated metal parts. In this paper, the specimens of stainless steel were made by the combined Selective Laser Sintering and Cold Isostatic Pressing forming route. And the simulation of Cold Isostatic Pressing was carried out by finite element method and Drucker-Prager-Cap constitutive model in ABAQUS/Explicit computer program. The property of metal powder was measured by experiments. The effects of bag on Cold Isostatic Pressing have been discussed. It is different from the Cold Isostatic Pressing of metal powder that the bag has little influence on both shape and size of the specimen. The results of simulation show a good agreement between the experimental results and the calculated results. The simulation can give a useful direction to dimension and shape designs of the combined forming of Selective Laser Sintering and Cold Isostatic Pressing.

Abstract: Through the comparative study of several enrichment machines ,the performance of the high-speed washer is introduced. The high-speed washer has high dewatering and washing efficiency, he pulp can be concentrated from 0.8% ~ 1.5% consistency to 10% ~ 15%;And it has high ash removal rate and good pulp washing effect also. It can effectively remove the ink particles, fillers, and other small impurities, improve the pulp brightness. At the same time ,the waste paper deinking process treatment systems has been developed.

Abstract: In practical centrifugal compressor fault diagnosis, it is very difficult to improve the fault recognition rate, especially when the sample sizes are small. To solve this problem, a new fault recognition method based on fuzzy gray relational grade was proposed. Firstly, according to fuzzy set theory, the fuzzy relation coefficient (FRC), fuzzy relation degree (FRD) and fuzzy relative weights (FRW) of all fault features were calculated. Secondly, the gray system theory was used to obtain the gray relational coefficients (GRC). Thirdly, by combining FRW and GRC, two fuzzy gray relation grades (FGRG) were presented, which is the Hamming distance-based fuzzy gray relation grade (HD-FGRG) and the Euclidean distance-based fuzzy gray relation grade (ED-FGRG), respectively. Finally, the fault recognition results were obtained by using the max membership degree principle. The centrifugal compressor fault diagnosis results show that the ED-FGRG method is more effective and accurate than traditional gray relational analysis (T-GRA) method, the weighted gray relational analysis (W-GRA) method, and the entropy weight-based gray relational analysis (EW-GRA) method and the HD-FGRG method.

Abstract: Rough sets theory (RST) and Fuzzy Petri nets (FPN) have been widely used in fault diagnosis. However, RST has the weakness of over-rigidity decision, and FPN has the dimensional disaster problem. In order to solve these shortcomings, according to complementary strategy, a new fault diagnosis method based on integration of RST and FPN was presented. Firstly, RST was applied to remove redundant fault features and simply fault information, so that the minimal diagnostic rules can be obtained and the fault was roughly diagnosed. Secondly, the optimal FPN structure was built and the fault diagnosis was finally realized through matrix operation of FPN. Finally, a diesel engine fault diagnosis example was analyzed, and the results show that the proposed method not only holds the ability of RST for analyzing and reducing data, but also has the advantage of FPN for parallel reasoning, so it has strong engineering practicability and validity.

Abstract: The experiment on the friction and wear of the lithium grease is done by choosing the ZrO2 nanoparticles as the additive in order to study the change of the tribological property of the lithium grease. The friction coefficient decreases by over 30% if the ZrO2 nanoparticles with the mass fractions of 0.25% and 0.5% are used as the additive. The ZrO2 nanoparticles with the mass fraction of 0.25% and 0.5% reach the best result and the wear scar diameter can decrease by 48.8% and 46.5%, respectively.

Abstract: Based on the chaotic theory, the methods of the Lyapunov exponent and the box dimension were applied to evaluate the chaotic characteristic and the nonlinear dynamic performance of the rolling bearing friction torque. The time series were obtained via the experimental investigation on the friction torque of the rolling bearings under the condition of different rotational speeds. It is found that the rolling bearing friction torque is of a chaotic system because the maximum of Lyapunov exponents of its time series is greater than zero according to the chaotic theory. And the result shows that the mean of the box dimension of the friction torque increases with the rotational speed of the rolling bearing, revealing the new dynamic performance of the rolling bearing friction torque as a time series.

Abstract: The article used the large span and heavy load cross-rail of some machine tools plant’s heavy-type numerical control milling planer for research object, by using the finite element software to build the model and force analysis. It also researched the force distribution and deformation condition of the large span motion girder under the actual working condition. It considered the slide carriage superposition effect to build the describing method and establishing process of the large span load curve by contacting analysis and restraining analysis, and got the knifepoint trajectory deformation. The research provided the sufficient theory basis and simulation method for designing improvement of cross-rail structure and got a perfect arch in advance.