Advanced Materials Research Vol. 711

Abstract: The paper analyses the impact of increase pressure on the value of ultimate tensile strength UTS and the Brinell hardness of HB castings made of silumin ENAC 47100 (AlSi12Cu1 (Fe)). Experimental observations enable to determine the dependency between the observed mechanical properties of pressure Al-Si castings and one of the basic parameters of die casting increase pressure.

Abstract: This paper reports the results of experimental research concerning the connection between the deck plate and the web of the longitudinal stiffeners in an orthotropic plated bridge deck on a microscopic scale. An important number of test specimens of a weld are studied with the help of a video microscope, to detect the efficiency of the root of the weld. The second part of the paper is concerned with parametric analysis of the lack of weld penetration by using accurate finite element modeling. The results demonstrate that the weld quality often required cannot always be assured, which surely has important consequence on the stresses in the weld and the fatigue resistance.

Abstract: In the present study, TiO₂-nanofluid with different volume ratio was used as working fluids of thermosyphon and grooved heat pipe to investigate working stability. The stability behavior of system was studied with various parameters such as volume concentration of nanoparticle, orientation, heat flux, and cooling media were investigated. Specially, the present experimental unstable working behaviors between TiO₂-nanofluid and pure water were compared. In the present study, the TiO₂-nanoparticles were dispersed into pure water with each of cross blended concentrations of 0.05%, 0.1%, 0.5%, and 1%. In the present study, the rate of growth of unstable disturbances is expressed in terms of temperature perturbation. The best stable operation was observed with thermosyphon of 0.5 % TiO₂-nanofluid. The best operation state with nanofluidic TS was observed in the 90° inclination and α = 0.5. In the present study, the enhancement of heat pipe performance with TiO₂-nanofluid is presented. The both heat pipes were fabricated from the straight stainless pipe with the inner diameter and length of 10, 500 mm, respectively.

Abstract: In the papermaking process, improve the efficiency of dehydration is the most important part of the control system of the paper machine press section, in order to improve the the papermaking efficiency and the quality of paper, the paper analyzed, the shoe working hydraulic oil passage analyzed.

Abstract: In recent years, with the development of the automobile industry and urban traffic, the pollution of road traffic noise in Harbin has become more and more deleterious. After a detailed survey, it was found that the study about the situation of traffic noise pollution in Harbin was less and the result of evaluation was not accurate enough. In addition, the monitoring spots selected were so many that the workload was too heavy. Aim at this phenomenon, a new and comprehensive monitor on road traffic noise in Harbin and evaluation studies was done. The research was according to the state standards. The selected 35 road sections, the source of traffic noise and the state of traffic noise in Harbin and the state of traffic noise pollution were monitored detailed. The temporal and spatial distribution analysis on the source of traffic noise pollution in Harbin was carried out according to the monitoring datum. Through the monitoring safety analysis and overall character analysis on the state of road traffic noise, it was educed the phenomena of road traffic noise was serious pollution in Harbin. The mean value of equivalent continuous sound pressure level was 72.5dB, exceed state criterion about 2.5dB. Traffic noise of region was concluded that Daowai district>Daoli district>Xiangfang district>Nangang district by the traffic noise monitoring and safety analysis. Finally, the researchers found out the main factors which influence the state of road traffic conditions in Harbin based on the previous studies, and provided the countermeasures to reduce the noise.

Abstract: In this research we present multi-body dynamics analysis can be applied in product development using a case study of a Molded Case Circuit Breaker (MCCB) with a spring-actuated linkage, which can save time and cost considerably. In particular, we demonstrate how to evaluate and improve durability of the MCCB based on multi-body dynamics and finite element simulation given SM45C steel used for the MCCB links. Toward this goal, a 3D MCCB dynamic model is first developed and dynamic forces are analyzed by using the multi-body dynamics software, ADAMS. Finite element simulation is then performed to examine maximum principal stresses considering deflections and dynamic loads. Further, mechanical properties of SM45C steel are measured experimentally from tensile and fatigue tests. As a result, we verify that stress loads acting on the latch pin of the spring-actuated linkage are critically higher, which ultimately leads to a low-cycle fatigue fracture of the pin. Based on our analytically estimated maximum principal stresses in the MCCB and experimentally measured mechanical properties of SM45C steel, we evaluate design durability and improve our design. As a result, using a 4 mm diameter pin and modifying SM45C with heat treating that includes quenching and tempering, we successfully achieve a MCCB product development, which provides sufficient strengths to prevent yielding and fatigue failures from repeated dynamic loads.

Abstract: In this research we investigate dynamic responses and vibration of a cantilevered beam subjected to a moving mass with variable speeds. Governing equations of motion under a moving mass are derived by Galerkin's mode summation method considering the effects of all forces acting on the beam (gravity force, Coriolis force, inertia force caused by a slope of the beam, and transverse inertia of the beam). A Runge-Kutta integration method is then applied to calculate dynamic responses of the beam. The effects of the speed, acceleration and the magnitude of the moving mass on the response of the beam are investigated in these numerical analyses. Furthermore, experimental tests are conducted to validate our analysis.

Abstract: Seismic wavelet plays an important role in the processing and interpretation of seismic data. And wavelet is also the premise of forward modeling and inversion of seismic wave. So it is important to study the formation process and formation rule of seismic wavelet. The viscoelastic properties of geologic body can be represented using Kelvin medium. The formation rule of seismic wavelet was analyzed using the mathematical model of propagation process of rectangle pulse in Kelvin medium. The experimental results have shown that characteristic frequency and band width were major frequency spectrum parameters causing the variation of waveform. The characteristic frequency and band width decreased with the increase of propagation distance. The characteristic frequency decreased in negative exponential law and became stable finally. The change of characteristic frequency and band width was related to the mechanical parameters of medium. With the increase of propagation distance, characteristic frequency decreased more slowly as elastic modulus increased than as viscous coefficient increased. The correlation coefficient increased with the increase of propagation distance, i.e., waveform became stable at last. Ratio of stability distance to characteristic wave length increased with the increase of elastic modulus and the decrease of viscous coefficient, then tended to become stable.

Abstract: In this paper, the generation theory of straight bevel gears with is studied. The movements of machine tool are first analyzed. Based on the meshing theory and differential geometry principle, the mathematic model for the generation of gears is established and the tooth surface equation of straight bevel gears is derived. Computerized simulation of generation process has been done, which lay theoretical foundation for rebuilding of machine tool.

Abstract: Fatigue problems about large sized structure components ,such as bridge crane girder , has always been the bottleneck of mechanical products lightweight, reliability, security. In order to study fatigue problem about crane girder in the actual conditions, the dangerous spot of the girder is identified by using the finite element method to analyze structural stress. By simplified model , set up to reflect the main beam welding details of the characteristics of the small size of the process welding fatigue specimen model, and carried out a series of fatigue life test. Specimen fatigue test results quantitative descript the actual fatigue life of the bridge crane girder welded structures. By data fitting, the S-N curve equation of the bridge crane girder include the specific materials, the stress ratio, the welding process and special structure is obtained. It provides a scientific basis and practical methods to solve weld fatigue life design and the remaining life prediction about the crane girder.