Advanced Materials Research Vols. 228-229

Abstract: Carbon fiber composed with epoxy-matrix is revealed to be a kind of functional composite material, which has sound sensing characteristics. The sensing ability of mechanic-electric character and temperature-electric character of carbon fiber layer based on the epoxy matrix was experimentally discussed in this paper. Through the uniaxial tension the CF layer reveals a good performance by resistance changing with response to the loading. In temperature-resistance testing, CF layer also has a good response to the temperature changing by its resistance varying. Carbon fiber composed with polymer will provides a new kind of sensor which can be used as force sensor and temperature sensor as well.

Abstract: Material is physical basis and carrier of design, which is a very important part of product design. On the one hand, designers can make innovations on traditional shape through using new materials; on the other hand they can make it from new materials and techniques for reference. The author put forward a subject of “designing for sitting” in teaching, asked the students to think from the perspective of material and finish the prototype, good effect has been obtained through this training. The pictures used in this paper were schoolwork of partial students who major in art design of North China Electric Power University, thanks for their passion and creativity.

Abstract: When a reinforced concrete structure suffers from a big fire, its quality will change and its bearing ability will be reduced. It is necessary to take a comprehensive testing and to formulate corresponding reinforcement to restore the structure. This article mainly talks about a series of detections and their results of a reinforced concrete culvert which suffered from fire, and then selects a better reinforcement program. It can provide reference for the reinforcement of similar concrete structures.

Abstract: The axle housing manufactured by hydroforming can meet the requirement of light weight in automotive making. The products are of reasonable thickness distribution, high strength and rigidity. The application time of hydroforming axle housing in automotive manufacturing is not so long, its theory and process research is still not enough, accumulation of its experiences of test data and deformation regulation is rare, all this lead to difficulty in manufacturing design. Aiming at above problems, this thesis takes 1:2 scale samples of a 0.75t truck axle housing to hydroforming test and research, so as to search the regulation of axle housing hydroforming. By the use of different loading path in the two step of the processing, reasonable loading paths to the axle housing hydroforming are found. By the study of the broken tube, hydrorming limit diagram is drawn.

Abstract: The purpose of this paper is to provide theoretical support for the structural design to prevent the wear of needle. The actual wear of the orientation part of the needle in scrapped needles was researched. The presented results showed that the main reason to the wear of the orientation part of needle was the dynamic instability and the abrasives enter into the surface of orientation part which increases the wear, and that the calculation model of dynamic stability was proposed to prevent the wear of needle. This model was a pressure rod, one end of which was fixed, the other was free, and the two ends were pressed on axial force which changes with time. Besides, the classic formula of dynamic stability of pressure rod was changed rationally, so as to correspond with the calculation model. It will play a part in preventing the wear of needle.

Abstract: To detect circuit breaker mechanical failures that are still in their early stages in order to avoid more serious failures and ensure reliable and safety of the grid operation, we uses a type ZW17-40.5 35 kV circuit breaker to simulate three typical incipient mechanical failures about stagnation of the energy storage spring, the dowel on the connecting rod and the moving arc. This analysis uses a digital camera detection method to record the processes for normal circuit breaker opening and closing conditions and conditions under stagnation. Additionally, by using a specially developed software to extract travel, speed and acceleration of specific location in every frame, we can discover features of the mechanical failure from the resulting data. This article provides a basis for identifying characteristics of stagnation and state monitoring of circuit breakers.

Abstract: Electronic corona may be obturated when dust load at inlet of ESP is more than 500g/Nm3, it will influence dedusting efficiency. Through analysis on current and electric intensity, we set up experiment device and use WS corona wire, fishbone corona wire, long dentation corona wire, V15 wire and RS corona wire to test their volt-ampere characteristics. This experiment indicates that the corona current produced by V15 and long dentation corona wires is higher, i.e. we can get higher corona current under same voltage to produce stronger corona discharge and electric wind, and it has little possibility to occur corona obturation in electric field. We can get the conclusion that V-typed corona wire is more suitable and economic for high dust load application.

Abstract: In tissue engineering, paraffin spheres are often used as porogen in solvent casting/particulate leaching technology to prepare scaffold. Shape, size of paraffin spheres is very important to connectivity of scaffold. Emulsification is commonly used to prepare paraffin spheres, in which the paraffin size can not be controlled well. In this paper, a new method based on digitalization of microfluids technology is used to produce paraffin spheres. In this method, relationship between drive voltage U and diameter of spheres, and relationship between diameter of nozzle d and diameter of spheres are studied. The two parameters have great effect on the shape, size of paraffin spheres. The shape, size of paraffin spheres can be adjusted by controlling the drive voltage U and diameter of nozzle d. The results show that the method based on digitalization of microfluids technology is simple, highly controllability.

Abstract: Aiming at the situation in some Chinese auto companies that the workload of body welding quality inspection is high and the sample size is extremely small, a brand-new CUSUM Control Chart for variance monitoring is proposed in the paper to realize the effective quality control in body welding variance, whose principle is to use variance statistics based on Queensberry transformation Φ-1(G((n-1) St2/σ02)) to monitor infinitely small variances in the process of body welding. Evaluation instance results show that, compared with traditional CUSUM control chart, EWMA control chart and weighted CUSUM control chart, the proposed CUSUM control chart based on variance monitoring is more sensitive to the abnormal variation fluctuation and can detect the abnormity of quality variation earlier.

Abstract: Aiming at some DTH drill key parts of fracture phenomena often appear, the paper analyzes its fracture characteristics, under load conditions and fracture process, and indicating the fracture is the main cause of fatigue damage. Also according to the theory of fatigue, the article illustrates the material of surface treatment, geometric structure adjustment and precision, and prolongs its service life.