Applied Mechanics and Materials Vols. 215-216

Abstract: Dimension feature recognition plays an important role in feature recognition in 2D engineering drawings. At present, in most dimension feature recognition methods, the first step is the recognition of whole feature, and then to extract feature information. These methods have some disadvantages, especially in exploded dimension feature recognition. Aimed to solve this problem, this paper introduces a new algorithm of intelligent dimension feature recognition. According to the position relationship with basic elements of dimension, the dimension is recognized in a bottom-up approach. This new method can solves the problem of recognizing the exploded dimension

Abstract: A 3D coordinate measuring method was determined on the basis of the analysis about structure of the auto fan; plan of the key point data collection was stated; Pointed out the whole process of computer aided and reversed design which includes from choice of key point, curved fitting, curved surface to 3D design.

Abstract: A practical approach for analyzing the waste heat boiler with fuzzy parameters is developed. The methodology involves integrated finite element modeling and fuzzy analysis. The uncertainties in the material, loading and structural properties are represented using convex normal fuzzy sets. Vertex solution methodology that is based on α-cut representation is used for the fuzzy analysis. The values of the extreme responses at an α-level are obtained by applying the binary combinations of the fuzzy variables that result in extreme responses to the finite element model. The merit of the proposed methodology is computational efficiency without compromise on accuracy and this is demonstrated through the engineering problem.

Abstract: Reasonable simplification of finite element modeling of complex mechanical systems can reduce the amount of elements and nodes. The solution efficiency is improved in this way, which is of great economic significance in the practical engineering problem. Based on the modeling and simulation of a Conveyor System between Roving Frame and Spine Frame in automated textile production line, this paper investigates and proves the effectiveness of simplification of the complex mechanical system in the dominant finite element software – ANSYS. Results of static analysis of the simplified model agree well with the actual data, proving that the simplified solid-beam element model of the Conveyor System is reasonable. The results lay the foundation for the subsequent kinetic analysis and optimal design of complex mechanical system.

Abstract: In order to predict the result of impact test in the design phase and reduce the experimental times, which can save cost and shorten development cycle, a finite element model of aluminum alloy wheel 13-degree impact test is established based on Abaqus. All mechanical parts such as the standard impact block, the assembly of the wheel and the tire, the support and bolts are included in the finite element model. The predicted result of finite element analysis and the experimental result agree very well shows the finite element model is correct. The equivalent plastic strain value was also put forward as fracture criterion for the wheel in the impact test which realizes the transition from the qualitative analysis to the quantitative analysis in the development process of aluminum alloy wheel.

Abstract: In order to validate the force analysis between cycloid gear and pin wheel, the paper built the contact FEM model of between cycloid gear and pin teeth, analyzed statically three-dimensional contact analysis for them and get their contact state. The calculation results coincided with the force analysis method and proved the correctness of the stress analysis theory.

Abstract: Researched the longitudinal model of the powered parachute , and dynamic numerical simulated the entire gust response in FLUENT . In the experiment, set of three different cycles that with different ranges of the oscillation over the same period by the dynamic mesh. Analyzed and compared the motion parameters against the steady-state, the same period oscillatory motion can effectively ease the impact on the aerodynamic characteristics. The simulation show that: the active exercise of reasonable design parafoil can inhibit the unsteady aerodynamic interference caused by the gust.

Abstract: Curve fairing has an important influence on curve editing and geometric modeling. Though there has been several different kinds of fairing methods, Multiresolution curve fairing has higher efficiency and simpler algorithms. Different from existing multiresolution curve fairing, a new multiresolution approach is presented based on non-uniform semiorthogonal B-spline wavelets, which can be applied for NURBS curve fairing. It has no restriction to B-spline curves’ knot sequence. This method effectively overcomes the limit of uniform or quasi-uniform B-spline wavelets for fairing. A detailed example is given to show the effectiveness of this multiresolution fairing method.

Abstract: The environment of application for overhead crane CAD system has been satisfactory. The fitting hardware and software system should be used, the appropriate development style and usage model should be taken, and the emphases should be put on the development of programming. That’s the most important thing the crane plants should do.

Abstract: This paper builds dynamical models and hydraulic system models of retraction/lowering of some regional aircraft nose landing gear respectively based on the software LMS VL motion and AMESim. The simulation analysis result was proved to be credible by checking with that of ground test. The peak oil return pressure with the critical damping force can be obtained by analyzing the hydraulic damping characteristic of actuator cylinder during landing gear emergency lowering based on methods of estimation and co-simulation. The results indicate that the damping characteristic of actuator cylinder plays an important role in emergency lowering. Only when the damping force breaks through the critical value, can the landing gear succeed in emergency lowering and being locked. However, the little damping force will result in great impact load while lowering. Thus, damping force should be changed only when emergency lowering.