Applied Mechanics and Materials Vols. 215-216

Abstract: Based on the methods including modified Mohr-Coulomb yield criterion, Lagrange and smoothed particle hydrodynamics (SPH), the cassava stem - root - soil system dynamics simulation model is established by ANSYS/ LS-DYNA. The interaction mechanisms between uprooted cassava root and soil are discovered. The processes of soil shearing and the changing processes of root's stress are analyzed. The studies show that (1) the effects of root being extruded on the soil expand gradually from inside to outside in the process of uprooting, and the uprooted force reaches the maximum value when the soil appears ring shear rupture; (2) after the uprooted force reaches the maximum value, the root's effective stress still increases gradually with the increasing of its bending deformation until the soil is separated,and root's maximum effective stress appears in the combination of the root and stem where is the most easily to be broken;(3)when the maximum uprooted force on cassava root is analyzed, the interaction of a disc and its extension on the soil is regarded as the mechanical model of maximum uprooted force on cassava root.

Abstract: Based on the methods including modified Mohr-Coulomb yield criterion, Lagrange and smoothed particle hydrodynamics (SPH), the digging shovel - stem - root - soil system dynamics simulation model is established by ANSYS/ LS-DYNA. According to the model, the interaction mechanisms among the digging shovel, soil and root are discovered, and the processes of soil shearing and the changing processes of root's stress are analyzed. The mechanisms of shovel's soil loosening are discovered. The process of soil deformation, fracture and loosening and the changing process of root's stress on micro level are studied. The results show that (1) the main reasons for soil loosening in the digging shovel operation are that the soil on the wedge is bended fracture due to being squeezed and uplifted, and that the soil is sheared and broken in the direction of the wedge's normal, and that the soil has no supporting of the blade so that a lot of fractures appear on the soil and is separated by the shovel blade, and that the upper and lower soil can't be closed; (2) when the wedge's extrusion attains a certain value, the links of root and soil will be destroyed; (3) the soil stress value around the wedge is largest, and the soil shearing rupture develops from bottom to top, and the shearing rupture surface occurs in the widest place of shovel blade in the direction of wedge's normal; (4) when the blade's tail points at the root, the root's effective stress is largest and makes the bending deformation of root forward and upward in the meantime, and when the root's effective stress is too large, the root will be broken and the harvest will be lost.

Abstract: This paper introduced the method that developed model and frequency analyses of powertrain mounting system based on ADAMS (Automatic Dynamic Analysis of Mechanical Systems ). The six vibration frequencies and its corresponding modes were obtained and compared with experimental results. Mount stiffness of the four mounting parts were optimized to use Adams/Insight. The former low decoupling degrees and the new part stiffness were observed to improve the disadvantage and can reduce the vibration transfer.

Abstract: This document explains and demonstrates how to analyze the stress of the axle, modify the rear wing and SolidWorks dynamic simulation analysis for the F1 Race Car. It offers a variety of results visualization tools that allow investigators to gain valuable insight into the design of the F1 race car, and makes it easy to share analysis results effectively with everyone involved in the F1 race car product development process.

Abstract: The conventional finite element modeling of the tower in the ANSYS GUI, in particular, the modeling of the whole tower crane which is large and complex, always gives rise to low efficiency and less authenticity. A new method of modeling of whole tower crane is presented here. This paper applies the APDL which stands for ANSYS Parametric Design Language to separately build crane’s components :the mast, the tower head, the counter-jib ,the jib and the simplified slewing platform. And then accomplishes the parametric finite element model of the whole tower by using the assembly and connection technology provided by ANSYS to assemble and connect them. Further, based on these methods and Visual Basic Programming Software, the parametric design software on tower crane has been developed. At the end of the paper, the paper takes the H25/23 tower crane as an analysis example to demonstrate that such a method is not only technically feasible, but also cost-effective. The details of the parameterized modeling and related technologies are given in the paper.

Abstract: By analyzing the chart data and formulas in the traditional design of the roller chain, together with the SolidWorks modeling features, a fast modeling method of roller chain drive is presented on the basis of the main parameters in the chain drive design. In virtue of the Curve Driven Array, the chain modeling is executed in parts environment, with the track dimension property changed and the dimension driven mathematical formula established to correct the error between theoretical calculation and practical graphics, which ensures a successful array and provides an effective way for the rapid 3D model establishment of chains and the chain drive assembly.

Abstract: This paper took 180 ton converter of Anshan Iron and steel Group as example, simulated the process of converter titled holding applying 3D simulation software, calculated the torque of empty converter and liquid steel in initial trunnion position, determined the best position of trunnion , calculated the tilting torque of the converter finally. The method is simple, accurate, graphic and practical, it provides a simple means for the design of converter equipment.

Abstract: Finite element analysis software ANSYS is used to establish a three-dimensional finite element model of the pipeline corrosion defects by applying the boundary conditions of square wave excitation to simulate the distributions of current and induced magnetic field in the pipeline under various defect volumes. The results of the study show: When there is no corrosion defect in the pipeline, the electric current in the pipeline is basically even distribution. The magnetic field is distributed for the symmetrical vortex shape from head to foot, and it has not obviously gather phenomenon. When there are some corrosion defects in the pipeline, the electric current forms partial symmetrical vortex shape in both sides of the corrosion defect, and it is obviously assembled in the defect place. The simulation results of the different size defects show that the maximum magnetic field strength and the maximum current value increase with the defect depth increasing, while the output voltage decreases with the defect depth increasing. For the analysis of the stress distributions of the pipeline corrosion defect with certain size under different pressures, it was found that the maximum stress is 596 MPa when the bearing limit work pressure of the pipeline is 7 MPa, which is smaller than the yield strength with ensuring the safely running of the pipelines with defects.

Abstract: In order to describe the NC processing path better, and easy to realize path in a smooth transition of inflection point, this paper puts forward a kind of adjustable form of the cubic spline interpolation function; using the function can describe line, arc and freecurve, and realize smooth transition of inflection point through the control points which near the inflexion point. The spline function is of cubic polynomial, which calculation is simple, and it is easy to realize the operation of fast interpolation; it not only can describe various of NC paths, but also can be easy to realize the high speed of smooth processing between the NC orbit segments, which meets the needs of modern numerical control system for high speed, stability and flexible.

Abstract: A great change in mechanical industry has occurred after several successful practices using MBD (Model Based Definition) of The Boeing Company. It is an inevitable trend from two-dimensional product definition to three-dimensional product definition in mechanical industry. In China, two-dimensional design is widely used, and many enterprises have started to use three-dimensional design. Several standards for MBD have emerged around the world. This paper takes the planet shelf in planet driver system as an example, explores the revolved parts modeling methods based on MBD and Pro ENGINEER, and then makes a conclusion. Following these methods we can build a model which conforms to MBD standards correctly and efficiently.