Polymers in Concrete
Materials Structure & Micromechanics of Fracture VI
Functional Manufacturing Technologies and Ceeusro II
Fracture and Strength of Solids VII
Components, Packaging and Manufacturing Technology
Silicon Science and Advanced Micro-Device Engineering I
Progress in Functional Manufacturing Technologies I
Science and Processing of Cast Iron IX
Bridge Health Monitoring, Maintenance and Safety
Manufacturing Automation Technology Development
Computational Methods in Fracture Mechanics
Advances in Fracture and Damage Mechanics IX
A New Sight towards Dye-sensitized Solar Cells: Material and Theoretical
Progress in Functional Manufacturing Technologies I
摘要: A micro grooved finger has smaller bending stiffness and can be used to improve the performance of some micro cantilever devices. The deflection and bending stiffness of a micro grooved finger are discussed in this paper. An analytical model of the deflection is built up to study the effect of the groove sizes on the bending stiffness and the deflection of the grooved finger. The calculation of the analytical model is consistent with the simulation and experiment results. When the grooves depth is 0.5 μm, the spring constant of grooved micro finger is 19.8% smaller than that of flat finger without groove patterns. The spring constant of the finger decreases with the increasing of the width and depth of the groove. A novel micro electric-thermal gripper is introduced based on the grooved finger. It consists of four sub-cantilever beams arranged at the diagonal lines of the square frame in the end of the main cantilever structure suspended from the silicon substrate, which guarantees an effective contact by the four-point contact area on the top surface to grab object of importance. The thermal expansion induced deflection makes the fingers moving vertically from an ‘open’ position to a working one. The grooved fingers help to decrease the bending stiffness of the finger and increase the deflection and the initial gap. The simple fabrication process has a feasibility of compatible and mass production.
摘要: In view of the product shape prototype's information model, based on the fuzzy D-S inference establishment product shape meaning matrix's design style description method, determinates the product conventional shape meaning. Then, the shape description object's meaning word is proposed based on the most superior fondness's meaning connection. Finally, the analysis is carried on based on the design style space and the shape whole appraisal distribution map to the product, established the shape meaning matrix to express as the product design style description model computer formalization.
摘要: Aramid fiber is one of the most promising materials used in secondary structure of the airplane, which has many merits such as low density, abrasion resistance, impact resistance, permanent flame retardance etc. Current research at home and abroad is mainly on the manufacturing process, mechanical and electrical properties of aramid fibers while the sound absorption property research is less. We prepared aramid micro-perforated composite materials according to the theory of micro-perforated absorber, in order to test and analyse sound absorption properties of micro-perforated sound-absorbing materials with different thickness, aperture, perforation ratio and combined program by using acoustic standing wave tube measurement system. Experimental results show that: the absorption effect of the Micro-perforated Panel Aramid Composite is obvious, in a certain frequency; the absorption coefficient is greatly improved. The study offers a new method for aramid fibers which could be applied in planes and cars.
摘要: It is critical to control chip forming, regular curling and breaking in turning. One method most commonly used is to make chips curl and break with chip-breaking grooves. Chip-breaking groove designing is complex and affected by several factors. Cellular automata is especially used to solve problems in complicated situation, hence this paper adopts cellular automata to design curves of the grooves. After blending the curves through Pro/Engineer into part, an insert with three-dimensional complex groove was developed with EDM. The results of cutting experiment showe a great performance of the grooved insert in turning, reaching the expected goal, and feasibility to design a three-dimensional complex groove insert with cellular automata as well.
摘要: The processing of rough machining and semi-finishing of revolving body stone is studied, according to the particularity of stone machining. Based on the study of processing, the system of computer aided programming and simulation for the revolving body stone is mainly researched. This system integrates the NC code automatic generation module and numerically controlled machining simulation module and this system is able to verify the pre-existing NC code. Thus greatly improves the efficiency and raises the quality.
摘要: This paper proposed a new and effective parametric curve interpolation algorithm with error compensation capability for high speed machining. The proposed algorithm is developed from the first-order Taylor expansion interpolation algorithm and the speed-controlled interpolation algorithm. It is also incorporated the geometry features of the machined curves, the dynamic characteristics of machine tools and the adaptive error control. The proposed algorithm achieves high surface accuracy and avoids feedrate fluctuations. Simulation results have demonstrated the effectiveness and satisfactory performance of the proposed algorithm.
摘要: In this paper, we investigated the knowledge modeling and proposed an ontology description logic theory based on fuzzy interval in order to support the management and reuse of design knowledge. We also established the methods to classify and represent the concept-design knowledge and developed an ontology-based model presenting the design knowledge as well as a model for modeling cycles. We further applied these methods and models to develop a specific ontology-based design knowledge model and validated them in the management system of design knowledge for the construction machinery.
摘要: Fixtures are used to locate and constrain firmly a workpiece during machining operation. Flexible and efficient fixturing has become an important issue in flexible manufacturing systems and computer integrated manufacturing system. Locating planning is the basis of the fixturing design, which has a direct influence on the quality of the clamping scheme and the machining quality of workpiece. This paper presents a new approach for locating planning of workpiece. Firstly, it will automatically select the primary locating surfaces with consideration of 5 influence factors: constraint freedoms, surface feature, valid locating area, tolerance relationship and surface roughness. Then the other locating surfaces are determined by retrieving similar workpieces under the guideline of 4 locating methods which will make the best of already available locating planning. Finally the optimal locator layout is fast achieved with GA with the goal of minimal locating tolerance.
摘要: The part’s precision-machined quality of NC machining is influenced by the chord error greatly during precision machining. The confined chord error Algorithm for Machining Complex Parametric Curve is proposed for the complexity of the chord error. The information of the arc length error is utilized to control the chord error of the interpolated point indirectly. The arc length error of interpolated point is computed by Simpson expressions, the information of coordinate and the first order derivative of interpolated point is computed by the interpolation algorithm, so the computed difficulty is not increased greatly. The computed error of the algorithm is discussed and the simulation example of NURBS curve proves that the destined precision of the chord error can be satisfied by this algorithm.