Jia Yao

Impact Toughness Evaluation of Coir Mat Reinforced Unsaturated Polyester Composite

Coir mat reinforced unsaturated polyester composites have been prepared and the impact toughness has been researched, and the impact toughness model has been established based on the coir weight percentage content, the change laws of each mechanical index have been detailed, thus the optimal solutions have been put forward when the coir content was from 10 wt.% to 35 wt.%. The toughening effect of coir mat on unsaturated polyester matrix is remarkable, the non-woven needle mat of coir as the reinforced body for unsaturated polyester matrix is better than that of random distribution coir form.

Design of Spindle Dynamic Balancing Basing on Discal Work

This Paper analyzes the principle of high-speed spindle electromagnetic dynamic balancing device and designs a device driver. The device is a dynamic balancing system for high-speed spindle which guarantees the machine running normally and gives significantly improved part surface quality. According to the equilibrator and clutch working sequence the driver activating the balancing device was designed based on AT89C51 and PMM8713 to control the electromagnetic dynamic balancing device in real time.

Research on Flexible Specialized Curriculum System of Traffic and Transportation Major

Due to various influential factors, professional directions and characteristics of traffic and transportation varies among universities. This paper, taking Jiamusi University for example, discussed the specialized curriculum system of traffic and transportation major in the context of large engineering. Considering talent training characteristics and employment tendency of traffic and transportation, flexible curriculum system that combines students interests with employment orientations was developed in this paper to overcome limitations of current curriculum system. KEYWORD: traffic and transportation; major; specialized curriculum; employment orientation

Production Process and Nondestructive Testing of Soybean Stalks Particleboard

Orthogonal experiment of four factor and three level has been adopted, through the process analysis of the various factors on mechanical properties, the best process conditions of soybean stalks particleboard are chosen as: density is 0.7g/cm3, glue content is 12%, and hot pressing time distribution is 3+4 minutes, hot pressing temperature is 175°C. The Ef (the dynamic elastic modulus of NDT) of soybean stalks particleboard has been examined by flexural vibration method of FFT(Fast Fourier Transform), the regression between Ef and MOE(modulus of elasticity), MOR(modulus of rupture) is significant and existing high relevance degree, so using FFT method for NDT of composite materials is feasible.

Acoustic Absorption Performance Research of Coir Density Board

Coir fiber is one of the tropical fruit fibers, the effective use of coir is not comprehensive now and the phenomenon of resources waste still exists. Full study of the advantage characteristics of coir has important significance for the expansion of the application field of coir resources. This article determines the light porous characteristics of coir from the micro-morphological characteristics. Through the prediction model research of the sound absorption coefficient of the porous fiber materials, the optimization density and the optimization thickness ranges can be got for the coir density board, so as to guide the optimization design of the sound absorption performance of coir density board. The changing rule of the sound absorption coefficient of the coir density board has been got by adopting the wave impedance tube method and the sound absorption coefficients by adding 5cm air gap has also been researched. The results of the experiments confirm that coir density board can be used as a secondary noise absorption material; the practical applications of coir density board are as the lightweight wall, the car interior trim or seat filling materials and the shipping cabins materials, to reduce the corresponding environment noise.

Experimental Study on Axial Compression of FRP Confined Concrete Column

Abstract: Concrete members strengthened by fiber reinforced polymer (FRP) are increasingly becoming a popular retrofit technique in recent years due to the excellent material properties, convenient and easy construction methods, and outstanding strengthening effect. However, fundamental researches are incomplete; especially the characteristics research of square cross-section of FRP confined concrete has become a major obstacle for the development of further research and application. Therefore, the better understanding of the behavior of confined concrete becomes of paramount importance. A total of 10 concrete columns, which were reinforced with CFRP (carbon fiber reinforced polymer) and with filleted square sections, were fabricated and tested subjected to axial load to investigate the mechanical properties of FRP confined concrete. The mechanical behavior of FRP confined concrete has been further understood and some useful conclusions are obtained.

Establishment and Experimental Research of Performance Test Table of High-Speed Ball Screw Feed System

The high-speed processing performance test table has been built, the automatic return circuit test has also been designed to ensure convenience. The high-speed processing performance measurement test system has been established, the corresponding test results have been obtained. Finally, effective measures have been obtained through the rational analysis of the test results to improve the precision CNC(computer numerical control) machining.

The Micro-Mechanism of Vibration Cutting Stress Wave and the Analysis of Macro-Processing Effect

The specification of the vibration cutting loading is a decision factor for the generation of stress wave and the stress wave propagation has a significant impact on its micro-mechanism. Making the stress waves’ generation in the cutting area of vibration cutting for entry point, the analysis of internal inflection wave, inflection fracture and dynamic stress intensity factor has been carried out, the simulation of vibration cutting has also been done by finite element method, the essential of energy concentrated role, shear angle increment and cutting quality improvement has been explained.