Applied Mechanics and Materials Vols. 300-301

Abstract: In this paper, the authors built the test device for CFRP drilling machining and drilling force detection system. An experimental research was conducted on the drilling force of CFRP drilling. Based on the multiple liner regression analysis through SPSS software, the empirical formula, considering the spindle speed and feed rate, is presented for predicting the drilling force. The results obtained were satisfactorily validated by comparing the experimental findings with the corresponding theoretical data and it is possible to conclude that the model affords a focused approach to the definition of the most appropriate drill geometry and cutting parameters in composite materials drilling.

Abstract: This paper presents a new kind of retrieval and clustering solution for multiple disciplines design knowledge during complex product development. The main contributions of this study can be focused on four points: The first is to distinguish the concepts and contents of ontology theories and semantic web. The second is to map the distinction and relationship between concepts to similarity and correlation of product design knowledge. The substances of conceptual hierarchy are introduced and their formal descriptions are given in the article. The third is to explore the specific calculation methods for semantic similarity and relevancy using the above theories and approaches. Finally, a model for design knowledge retrieval if proposed, and the tactics for knowledge retrieval and clustering are given.

Abstract: Anti-climber is one of the most important passive safety devices for railway vehicles. Based on the non-linear finite element method, properties of the anti-climber with different vertical offsets are simulated by the software LS-DYNA. The force-displacement curve is mainly analyzed, and the energy absorbed by the anti-climber is also calculated in order to assess the properties. At last, an improvement method with a cross structure inside the anti-climber is designed for the offset problem and is proved effective by the simulation.

Abstract: This software is aimed at providing engineering design personnel who are engaged in marine gas turbine power system design and performance optimization with a software platform for concentrated design and management. First, the mathematical model of the sub-shaft gas turbine was established using volume inertia and rotor inertia method. And then the relative non-linear simulation module base of all components was built based on MATLAB/Simulink. Second, in order to develop this extensible simulation software for the study on the marine gas turbine overall performance, a human-computer interface was cultivated too based on MATLAB/GUI. This software provides the functions of analyzing dynamic performance of the marine gas turbine power system in both on-design and off-design operating conditions. It offers engineering design personnel an extensible and useful GUI platform in gas turbine system design and performance optimization.

Abstract: Through a systematic analysis of various aspects during the process of vehicle engine lubricating oil storage, transportation and use, this paper set up vehicle engine lubricating oil failure fault tree which chose the failure of vehicle engine lubricating oil as the top event. Through the analysis of the fault tree, the minimal cut sets of fault trees were figured out based on the Boolean algebra method. Besides, the structure importance was analyzed, and thus the failure detection process was given and some preventive measures were recommended.

Abstract: Availability is essential index for strategic weapons in storage mission. Spare parts replacement is an effective way to improve system storage availability. Normally, the performance degradation of spare parts before replacement is hardly considered in traditional instantaneous availability model. We established a instantaneous availability model using backward equation of semi-Markov Process (SMP) when considering the degradation time of spare parts before replacement. Our analysis indicated that availability had been great effect on when the performance degradation of spare parts is considered. An example is shown to express that this model could help policymakers to choose more suitable supporting plan.

Abstract: The dynamic characteristics of parallel 3-TPT machine tool are researched by experiment in this paper. Firstly, modal analysis principle of machine tool was analyzed in theory, and the parameters of dynamic characteristic were identified by theoretical analysis. Then vibration model of parallel machine tool was built and formed vibration system of rigid and flexible coupling for analysis. Then, the modal experiment method and steps were introduced, and the experiment parameters also were identified according to the experiment results. The result dates are showed that the result dates are validated. So the experiment method is feasible by experimental verification, which provides reference for dynamic optimal design.

Abstract: Experimental investigation results of the fuel injector group in a heavy-duty gas turbine are presented. Atomization characteristic has great impact about combustion, inflame, temperature field of outlet. Obtained atomization characteristic about spray particle size and spray angle using LDV/PDPA system, determined dimension of injector group. On the basis of these tests, the combustion testing of the injector group in the flame tube is made, its every targets are arrived in the design requirements. This has demonstrated: the test systems and test methods are practical, feasible and reliable. These experimental data have provided the reliable basis for the injector group design and development.

Abstract: To avoid the impact which is caused by the characteristics of the random fluctuations of the wind speed to grid-connected wind power generation system, accurately prediction of short-term wind speed is needed. This paper designed a combination prediction model which used the theories of wavelet transformation and support vector machine (SVM). This improved the model’s prediction accuracy through the method of achiving change character in wind speed sequences in different scales by wavelet transform and optimizing the parameters of support vector machines through the improved particle swarm algorithm. The model showed great generalization ability and high prediction accuracy through the experiment. The lowest root-mean-square error of 200 samples was up to 0.0932 and the model’s effect was much stronger than the BP neural network prediction model. It provided an effective method for predicting wind speed.

Abstract: This study aimed at investigating the perception of toothpaste flavors during tooth brushing. The 3D geometrical model of human oral cavity and nasal cavity was built. The dynamic concentration of investigated flavor limonene under certain tidal volume was obtained with computational fluid dynamics (CFD) technology. It was found that the designed taste could be reached within half minutes for limonene. According to the data within 180s, the taste did not changed significantly during the whole brushing time. Tidal volume was crucial for the perception for the toothpaste.