Applied Mechanics and Materials Vols. 157-158

Abstract: In the CAD software, we use the theory of free surface to model the blades of turbine, which makes it faster and effective to achieve surface CAD reconstruction and achieves the inverse modeling of turbine blades. All the works above provide physical model for the study of turbine blades repair technology.

Abstract: Aim at solving the problem that the target may exceed acceleration limit, a new passive tracking filtering algorithm based on “Current” Statistical (CS) model has been proposed. By designing nonlinear fuzzy membership functions, the new “Current” Statistical model filtering algorithm can adaptively adjust the acceleration upper and lower of CS model. Monte Carlo simulations of maneuvering targets show that the NCS algorithm has a better performance than the traditional CS algorithm.

Abstract: Based on the experiments, the parameters of acoustic emission signals were discussed about cracks, expansion and instability of concrete in this paper. The relationship between different acoustic emission signals of concrete were established on damage constitutive relation. A new method was provided by damage assessment for hydraulic structures.

Abstract: The Hard Disk Drive is the important components in the present computer. The Hard Disk Drive manufacturing need high productivity and cost improvement to support the market needs. Many cost reduction are done on product design, material cost and manufacturing operation. This work shows an idea to improve productivity and also reduce the scrap cost by rework process. The product performance will be considered to prevent the reduction of reliability and degradation.

Abstract: The necessity of the electric vehicle using energy regenerative braking system is described in this paper. Then the design process of the braking system with the super capacitor was discussed and the determination method and the control mode of the main technical parameters was analyzed. Using the system the electric automobile can realize regenerative braking in any common condition especially when the conventional regenerative braking can not be achieved. Under these circumstances the electric energy which is generated by braking process and stored in the super capacitor can output to the traction inverter DC link when the automobile is in the traction mode .So it is a good way to significantly reduce the electric vehicle energy consumption.

Abstract: To design high quality and efficiency discharging system, according to the analysis of strength and the study of discharging principle for bulk materials between general silo and central cone silo with discharge arms, their theoretical model and simulation model are established. Based on the theoretical calculation and simulation results, it is proved that the central cone silo which has a rotary discharge arm or discharge arms revolving around the central cone has advantages with discharging the difficult bulk materials, which could efficiently prevent the harmful discharging such as bridging, rat-hole and so on. Controlling the outflow of bulk materials, it is easy to automatically discharge the bulk materials and improve the efficiency of silo system. The result shows that the central cone is practical and the discharging way provides a new program for solving technology problems in discharging the difficult bulk materials.

Abstract: In this paper, nano-SiO₂ (NS), nano-Al2O₃ (NA) and nano-CaCO₃ (NC) were used to improve the mechanical properties of cement. Experimental results showed that the early hydration of cement was promoted by all of these three nanoparticles. When the content is 1%(NS), 2%(NA) and 1%(NC), respectively, the mechanical properties of cement got the best modification. Different nanoparticle had its own optimal content concerning modify the mechanical properties of cement. When the content was larger than 3%, nanoparticles nearly had no modification to cement and cement exhibited lower strength comparing with blank cement.

Abstract: This paper deals with the use of Programmable Multi-Axis Controller (UMAC) based on preview control method to give good trajectory tracking performance of 3-axis servo table. The paper consists of mathematical modeling, simulation, and an experimental work. Adopt the position coordinate method of three-dimensional space trajectory tracking. In this paper, based on previous research, it gives a trajectory tracking control algorithm, constructs an experimental system used to implement trajectory tracking, establishes its mathematical model, then uses the control algorithm to carry out simulation analysis, and finally uses the simulation results to carry out experimental study. In this paper, the experimental system, which decomposes object trajectory to various axes for tacking, is effective. It takes the best motion controller as the core, and takes servo motor as driving mechanism to drive precision positioning platform. It possesses of powerful real time and linkage performance, and the powerful hardware and software function enable it to have a wide range of applications.

Abstract: According to the requirement of collaborative product development, a networked collaborative design and manufacturing system is put forward. A neuter digital assembly model which is independent from all kinds of the commercial CAD software is set up. The quick planning of the assembly sequences and the automatic search of the assembly dimension chain can be realized by the simulation.

Abstract: In order to investigate the effectiveness of laser quenching for ceramic coated steels, 2 kinds of ceramic coated specimens of CrAlN and TiAlN were prepared, and the laser quenching experiments under various irradiation conditions were carried out. The influence of laser irradiation on the substrate hardness, film hardness and adhesive strength were investigated. Because of the high heat absorption of CrAlN and TiAlN films when compared to TiN, it was possible to quench the substrate effectively without any absorbent material for these specimens, although an absorbent was required for TiN coated specimen. The quenched area on the cross section of the substrate of CrAlN coated specimen was larger than that of TiAlN coated specimen. The difference of the quenched area could be explained by the difference of the heat absorption of these films. It was also possible to improve the adhesive strength of these films by laser irradiation. Although the film hardness decreased considerably by furnace quenching for ceramic coated steels, film hardness did not decrease by laser irradiation. It was concluded that the improvement of the adhesive strength and substrate hardness without the decrease of film hardness was achieved by laser quenching for CrAlN and TiAlN coated specimens.