Applied Mechanics and Materials Vols. 713-715

Abstract: The use of three-dimensional graphics software Solide-edge CAD model to establish the structure of the material wagon, by successfully importing finite element software, building material wagons fine finite element model based on finite element theory, the dynamic characteristics of the model was analyzed, the connatural frequencies and the corresponding modes of the frame was acquired. A simple experimental result was compared to verify the correctness of the finite element model, which provided the correct analysis model for the study of the structure of the frame damping.

Abstract: The reliability of mechanical component is a time-varied process because the parameters such as operation condition, load, strength, are varied with time or the loading numbers. This paper builds the time-dependent reliability model when life is measured by the loading numbers. The variety-law of component’s reliability with the lifetime is derived from the built model and simulation of picking link rod used in sewing machine. It is shown that the time-dependent reliability model is effective and the reliability of component decreases obviously with the time and the increasing load standard deviation.

Abstract: This paper estimates the fatigue residual life of bridge crane with probability distribution model of stress spectrum, which influences the main parameters of the stress characteristics of the fatigue accounting point.Random sample of load spectrum parameters are produced by Latin hypercube.We can use the dynamic simulation model to calculate the stress-time history during the entire simulation at the accounting point of fatigue,and then with rainflow counting to obtain the double parameters stress spectrum. The result is that the bridge crane has 22630 lifting cycles and 37566 stress cycles in two years of an inspection cycle, and stress spectrum includes 10 stress amplitude and mean stress.

Abstract: The time-dependent reliability model of Mechanical Component is influenced by many parameters such as stress, load, strength, strength degeneration and lifetime index. This paper builds the time-dependent reliability model when life is measured by the loading numbers. The variety law of mechanical component’s reliability with the lifetime is derived from the built model and simulation of link rod in needle bar mechanism used in the sewing machine. The result shows that the time-dependent reliability model is effective and the reliability of component decreases obviously with the loading numbers when the strength degeneration is considered.

Abstract: Rapid prototyping technology can generate parts directly from the three-dimensional CAD entity data, hierarchical algorithm is a key link in rapid prototyping manufacture. In this paper, mainly used a hierarchical approach in RP equipment,for the study aimed at three commonly hierarchical algorithm (hierarchical algorithm based on STL model, direct sliced of CAD models, Smart Slice based on STL model) by Perspective, trying to provide a reference for the stratification algorithm of RP system by comparison of the three tiered approach,This paper argues that the Smart slicing algorithm based on STL model is more accurate stratification algorithm

Abstract: This study focuses on the smoothly blending problem of two cylinders whose axes are non-coplanar at the clipping planes which are perpendicular to the axes. Based on the condition that the axes were smoothly blended, we presented the necessary and sufficient conditions of the existence of the blending surface with the cylindrical helicoids tube constructed. And when those conditions were met, we presented the specific blending examples.

Abstract: In order to obtain the accurate thrust rod load, based on the theory of multi body dynamics, establish the complete vehicle virtual prototype model by using ADAMS software, the dynamic simulation of the thrust rod load time history. Combined with MATLAB software to build three-dimensional space pavement model with harmonic superposition method, obtaining the thrust rod load under different conditions, the simulation results show that, the vehicle loaded with uphill turn thrust rod by the load of the largest, and bear in various working upper thrust rod load than the lower load. Consistent with the experimental results, illustrate the modeling method is correct, can quickly and accurately obtain the thrust rod load.

Abstract: The torque balancing equations and the torque equation of the turbine flow meter is deduced in the paper. The driving torque, the viscous drag torque and the bearing friction drag torque on the impeller is calculated by unsteady numerical simulation methods. The change rule of the various torques is gotten considering or not the influence of bearing drag torque. Also, the effect of different viscosity on the torque is calculated, which is used to explain the phenomenon of meter factor change law with the viscosity. It makes clear that the possibilities to improve the accuracy of the meter and to predicate the meter factor by unsteady numerical simulation.

Abstract: The calculation of the fundamental frequency for the beam system structures is the important content in the dynamic design of the structure. This paper takes the basic unknown numbers of the displacement method to express the deformation of each member in the beam system structure. The calculation method of the fundamental frequency for beam system structures is got by the energy variational method. The method is very simply and could provide reference for the design of beam system structures.

Abstract: In order to reveal the elastohydrodynamic lubrication characteristics under heavy loaded and variable velocity conditions, We carried out the relevant experiments by the self-developed optical interference EHL experimental device. Improved apparatus substitute screw for the slider-crank, and driven by stepper motor. Velocity mutation experiment carried out to discuss features of the oil film while the stepper motor speed instantly changes from the velocity of 0.23mm/s, 0.38mm/s and 0.52mm/s. It shows that extrusion effect and oil film sag emerge in acceleration instantaneous similar to zero entrainment speed even it is not, and end of oil film has a necking phenomenon distinctly.