Applied Mechanics and Materials Vol. 680

Abstract: Based on ANSYS, a finite elements method study is conducted on couple fields of fixed tube-sheet heat exchanger. On the basis on the calculating results, the paper tries to analyze and evaluate the reliability and parameter sensitivity of the couple field of fixed tube-sheet heat exchanger, so as to present references for the reliable design on the intensity of mechanical equipments.

Abstract: The present paper deals with the efficient use of new technologies boreholes will use thermal drilling Flowdrill. Analyze the state and qualities of the material before and after using drilling. Evaluate and recommend their potential customers in order to decide on the basis of the results obtained, productivity and quality requirements. In conclusion, the determination of the possible applications of the technology in practice after changing the properties of the material around the hole.

Abstract: The excavation of the tunnel will inevitably cause the displacement of soil layer, and then further threatens the safety of high-speed railway operation. Under the engineering background of high-speed rail’s box culvert, using the technique of MIDAS/GTS, the establishment is based on 3 d finite element model of tunnel, soil mass and box culvert, to analyze the effects of box culvert settlement that led by shield tunnel excavation. The research indicates that tunnel excavation causes settlement of box culvert to some large extents, the soil mass should be reinforced to ensure the safety of the high-speed railway operations during the shield construction.

Abstract: Concurrent green design of machine product proposed concurrent engineering method in the process of product design, reflect the green design idea, realize concurrent engineering and green design information sharing, so as to shorten developing period, reduce cost, enhance quality and protect environment. Connotation, basic characteristic and key technology about concurrent green design are discussed in the paper.

Abstract: In order to extract the faint fault information from complicated vibration signal of bearing, the correlated kurtosis is introduced into the field of rolling bearing fault diagnosis. Combined with ensemble empirical mode decomposition (EEMD) and correlated kurtosis, a feature extraction method is proposed. According to the method, by EEMD processing a group of intrinsic mode functions (IMFs) are obtained, then the IMF with maximal correlated kurtosis is selected, and the weak fault signal is clearly extracted. The effectiveness of the method is demonstrated on both simulated signal and actual data.

Abstract: Plate girders with corrugated webs with angles were developed in order to promote the flange local buckling strength of conventional plate girders with corrugated webs. The width to thickness ratio of flanges can be reduced with angles. However corrugated webs cannot contribute to the flexural stiffness and strength of PGCW, corrugated webs of PGCW-A can. A full-scale test was conducted to evaluate the flexural capacity of PGCW-A. As a result, the flexural capacity of a specimen of PGCW-A increased by 163% compared to a specimen of PGCW.

Abstract: The article demonstrates one of the ways to reduce uneven load distribution along the width of the gear wheels which can be used in place of expensive modifications of the tooth flanks (crowning). This can be achieved by appropriate selection of the shape of the gear wheels for example the disk shape. The presented numerical example illustrates the above possibility taking into account deformability of the wheel body.

Abstract: Various higher order shear deformation theories of Levinson, Touratier, Karama are utilized to calculate the natural frequencies of functionally graded beams. The governing differential equations are solved by an analytical method. The present results are compared with the results of Aydogdu which demonstrate the accuracy of various theories.

Abstract: In the northern frozen-soil region,the heaving soil’s low temperature is the key factor that impacts the stability of foundation. This paper makes the heat-stress coupled numerical analysis on the cold expansion effect of the pile foundation to the Ulanhot-Baicheng 500kV transmission line engineering by finite element software ABAQUS. Firstly, the seasonal frozen soil’s temperature field should be calculated. Then, the temperature value acting as the temperature model’s initial condition is put into the structure model for computation, which can help to get the pile foundation’s stress field and strain field. The results show that, the stress state of pile-frozen soil under external load can be reflected accurately through the finite element model and the related parameters proposed, along with the finite element software.

Abstract: The machinability of Al 6061 in 1D and 2D ultrasonic assisted turning (UAT) in terms of machining forces, surface roughness and hardness is investigated in this research. In order to perform the machining experiments, a 1D vibration tool and a 2D vibration tool are designed and manufactured. The cutting forces and surface roughness of the work-pieces in 1D UAT and 2D UAT are measured in different cutting speeds and feed rates and compared with that in conventional machining. To investigate the effect of the ultrasonic vibration on the material properties, hardness tests are performed on the work-piece material and micro-hardness tests are carried out on the chip specimens. The results showed that reduction in the cutting forces occurred in UAT. The results also showed that the surface roughness is exceled in UAT in comparison with the conventional machining. While no detectable effect of the ultrasonic vibration on the work-piece material could be observed, the chip micro-hardness experiments showed that the softening phenomenon occurred in UAT, which can be the cause of the force reduction in UAT.