预加速在汽车冲模中的应用与行程图设计

通过预加速在斜楔滑块中的应用分析,提出了预加速设计的必要性,从结构特点,应用情况,参数设计,预加速行程图设计等方面进行详细阐述,让模具设计者对预加速在滑块中的应用有更深的理解与掌握,供设计者与同行参考。

基于CATIA平台的汽车覆盖件翻边成形过程同步模拟

基于CATIA平台,开发了汽车覆盖件翻边成形模拟系统。系统将结构设计中模具结构行程图思想引入翻边成形模拟中,综合考虑了翻边方向、驱动角与翻边行程对实际工艺的影响,该系统可真实反映翻边运动关系,以及翻边镶块交刀对翻边成形过程的影响,并在求解计算前通过动画演示的方式进行运动仿真,对工具运动进行干涉检查。同时,系统将CAE模型作为CATIA的特征集成于CAD平台上,实现了CAD设计模型与CAE分析模型的同步更新,避免了平台转化过程中模型数据丢失与精度损失,缩短了CAE反复建模的时间,提高了设计效率。最后通过汽车后围外板的翻边实例分析,验证了系统的准确性和稳定性。

顶盖后横梁非标斜楔模具设计

汽车覆盖件模具设计中大量使用到斜楔结构,通过对顶盖后横梁的斜楔冲孔模的设计,总结了非标斜楔设计的注意事项及模具的运动干涉检查,以保证设计的可靠性。

健康教育在COPD患者的应用

目的 探讨健康教育在COPD患者中的影响.方法 将我院中医科2008年6月~2009年12月收治的年龄在41~85岁之间的COPD患者80例,随机抽样方法分为对照组和实验组,每组40例.对照组仅采用常规护理方法实施护理.实验组按照健康教育行程图进行护理.比较两组患者对疾病知识知晓情况、护理工作满意度,以及疾病急性发作率.结果 实施健康教育行程图的实验组患者对疾病知识知晓率、护理工作满意度、疾病急性发作率明显优于对照组.结论 通过对COPD患者实施健康教育行程图,可减少患者痛苦,提高对疾病发生、发展及治疗、护理、康复、预防等方面知晓率;提高患者对护理工作满意度;减少疾病再发加重率,提高患者生活质量,提高医疗护理质量.

Feature Relationship and Process Planning

Concurrent engineering(CE)involves the consideration during the design phase of the various factors associated with the life cycle of the product.Using the principle of CE,a feature-based CAPP system is proposed.On the basis of feature modeling,the system is able to reason feature relationships,produce feature digraph of a part,and decide the machining sequence of features.

The Method for Separating Texts from Mechanical Engineering Drawings

Aim To separate texts from graphics on mechanical engineering drawings. Methods By improved labeling run, the size of circumscribed rectangle and pixel density about the connected graphs on a drawing were gained, according to these value, texts not sticking to graphics could be separated from a drawing. The concept of appendant block was introduced, using the appendant block, texts sticking to graphics could be determined and cut. Results Texts and symbols on mechanical engineering drawings can be separated well. Conclusion This method is simple and fast, it does not destroy the shape of texts and symbols, it can be used for separating texts and symbols from all linear graphics.

Parallel Image Processing Technology of Surface Detection System

To improve image processing speed and detection precision of a surface detection system on a strip surface,based on the analysis of the characteristics of image data and image processing in detection system on the strip surface,the design of parallel image processing system and the methods of algorithm implementation have been studied. By using field programmable gate array(FPGA) as hardware platform of implementation and considering the characteristic of detection system on the strip surface,a parallel image processing system implemented by using multi IP kernel is designed. According to different computing tasks and the load balancing capability of parallel processing system,the system could set different calculating numbers of nodes to meet the system's demand and save the hardware cost.

A General Mapping Approach and New Travelling Wave Solutions to（2＋1）-Dimensional Boussinesq Equation

A general mapping deformation method is presented and applied to a (2+1)-dimensional Boussinesq system. Many new types of explicit and exact travelling wave solutions, which contain solitary wave solutions, periodic wave solutions, Jacobian and Weierstrass doubly periodic wave solutions, and other exact excitations like polynomial solutions, exponential solutions, and rational solutions, etc., are obtained by a simple algebraic transformation relation between the (2+1)-dimensional Boussinesq equation and a generalized cubic nonlinear Klein-Gordon equation.

Hot working characteristics of HEXed PM nickel-based superalloy during hot compression

To study the hot deformation behavior of a new powder metallurgy nickel-based superalloy,hot compression tests were conducted in the temperature range of 1020−1110℃ with the strain rates of 0.001−1 s^−1.It is found that the flow stress of the superalloy decreases with increasing temperature and decreasing strain rate.An accurate constitutive equation is established using a hyperbolic-sine type expression.Moreover,processing map of the alloy is constructed to optimize its hot forging parameters.Three domains of dynamic recrystallization stability and instability regions are identified from the processing map at a strain of 0.7,respectively.The adiabatic shear band,intergranular crack and a combination of intergranular crack and wedge crack are demonstrated to be responsible for the instabilities.Comprehensively analyzing the processing map and microstructure,the optimal isothermal forging conditions for the superalloy is determined to be t=1075−1105℃ andε&=10^−3−10−2.8 s^−1.

Modified constitutive model and workability of 7055 aluminium alloy in hot plastic compression

To obtain flow behavior and workability of 7055 aluminium alloy during hot deformation,hot compression tests at different temperatures and strain rates are conducted.True stress?strain curves of 7055 aluminium alloy under different conditions are obtained and the flow stress increases with ascending strain rate and descending temperature.For Arrhenius constitutive equation,each material parameter is set as a constant,which will bring forth large error for predicting flow behavior.In this work,material parameters are fitted as a function of temperature or strain rate based on experimental results and a modified constitutive equation is established for more accurate prediction of flow behavior of 7055 aluminium alloy.The effects of temperature and strain rate on power dissipation and instability are analyzed to establish a processing map of 7055 aluminium alloy.The dominant deformation mechanism for microstructure evolution at different deformation conditions can be determined and high efficiency of power dissipation may be achieved from power dissipation map.Meanwhile,proper processing parameters to avoid flow instability can be easily acquired in instability map.According to the processing map,optimized processing parameters of 7055 aluminium alloy are temperature of 673?723 K and strain rate of 0.01?0.4 s^?1,during which its efficiency of power dissipation is over 30%.Finite element method(FEM)is used to obtain optimized parameter in hot rolling process on the basis of processing map.

汽车模具自制斜楔设计

汽车模具是汽车覆盖件主要的生产工具。模具设计主要通过工法设计和结构设计来完成,结构设计最常用的就是自制斜楔的结构。根据斜楔的样式、行程线图和结构尺寸,设计出作业性好的自制斜楔,从而设计出优质的模具。

Travelling Wave Solutions to Stretched Beam's Equation: Phase Portraits Survey

In this paper, following the phase portraits analysis, we investigate the integrability of a system which physically describes the transverse oscillation of an elastic beam under end-thrust. As a result, we find that this system actually comprises two families of travelling waves： the sub- and super-sonic periodic waves of positive- and negative- definite velocities, respectively, and the localized sub-sonic loop-shaped waves of positive-definite velocity. Expressing the energy-like of this system while depicting its phase portrait dynamics, we show that these multivaiued localized travelling waves appear as the boundary solutions to which the periodic travelling waves tend asymptotically

The Effects of Psychological Schema in Communication Behaviors

This study investigates the influence of psychological schema and communication behaviors in communication. Just as different disciplines and theorists use different concepts for different purposes, individuals may have different mental patterns of communication depending on their experience. The effects of different psychological behaviors can differ dramatically. The process of culture acquisition and communication is extremely a complex psychological process. Psychological schema determines how communicators analyze other people＇s information and respond with their own judgment about the speakers＇ cultural perspectives. The negative effect of the anomalous individual psychological element is fundamentally a mental process. It has a deep impact on people＇s communicative behaviors.

Mechanical Behavior and Constitutive Equation of High Temperature Compression Deformation of IN706 Superalloy

IN706 superalloy is particularly sensitive to the parameters of hot working process.The flow stress of the IN706 superalloy was investigated during reduction deformation of 30%,45%,and 60%under the isothermal compression conditions of temperature at 1143–1393 K and strain rate at 0.01,0.1,0.5,and 1 s^(−1).The exponent-type Zener-Hollomon equation was used to describe the impact of strain and temperature on the thermal deformation.Meanwhile,the strain effect of various material constants,such asα,n,Q,and lnA,was considered in the constitutive equation considering the strain compensation,and the correlation coefficient R and the average absolute relative error were verified.On the basis of constitutive equation construction,the hot processing map of IN706 superalloy was drawn,and the instability region was obtained based on the Murty criterion.Results show that the reasonable thermal working process parameter window is strain rate of 0.1 s^(−1)and temperature of 1313–1353 K.

Experimental investigation on the wing-wake interaction at the mid stroke in hovering flight of dragonfly

This paper focuses on flow structures of the wing-wake interaction between the hind wing and the wake of the forewing in hovering flight of a dragonfly since there are arguments whether the wing-wake interaction is useful or not.A mechanical flapping model with two tandem wings is used to study the interaction.In the device,two identical simplified model wings are mounted to the flapping model and they are both scaled up to keep the Reynolds number similar to those of dragonfly in hovering flight since our experiment is conducted in a water tank.The kinetic pattern of dragonfly(Aeschna juncea) is chosen because of its special interesting asymmetry.A multi-slice phase-locked stereo particle image velocimetry(PIV) system is used to record flow structures around the hind wing at the mid downstroke(t/T=0.25) and the mid upstroke(t/T=0.75).To make comparison of the flow field between with and without the influence of the wake,flow structures around a single flapping wing(hind wing without the existence of the forewing) at these two stroke phases are also recorded.A local vortex identification scheme called swirling strength is applied to determine the vortices around the wing and they are visualized with the iso-surface of swirling strength.This paper also presents contour lines of z at each spanwise position of the hind wing,the vortex core position of the leading edge vortex(LEV) of hind wing with respect to the upper surface of hind wing,the circulation of the hind wing LEV at each spanwise position and so on.Experimental results show that dimension and strength of the hind wing LEV are impaired at the mid stroke in comparison with the single wing LEV because of the downwash from the forewing.Our results also reveal that a wake vortex from the forewing traverses the upper surface of the hind wing at the mid downstroke and its distance to the upper surface is about 40% of the wing chord length.At the instant,the distance of the hind wing LEV to the upper surface is about 20% of the wing chord length.Thus,there must be a wing-wake interaction mechanism that makes the wake vortex become an additional LEV of the hind wing and it can partly compensate the hind wing for its lift loss caused by the downwash from the forewing.

A framework for an integrated unified modeling language

The unified modeling language(UML) is one of the most commonly used modeling languages in the software industry.It simplifies the complex process of design by providing a set of graphical notations,which helps express the objectoriented analysis and design of software projects.Although UML is applicable to different types of systems,domains,methods,and processes,it cannot express certain problem domain needs.Therefore,many extensions to UML have been proposed.In this paper,we propose a framework for integrating the UML extensions and then use the framework to propose an integrated unified modeling language-graphical(iUML-g) form.iUML-g integrates the existing UML extensions into one integrated form.This includes an integrated diagram for UML class,sequence,and use case diagrams.The proposed approach is evaluated using a case study.The proposed iUML-g is capable of modeling systems that use different domains.

The Two-Dimensional Supersonic Flow and Mixing with a Perpendicular Injection in a Scramjet Combustor

A numerical investigation has been performed on supersonic mixing of hydrogen with air in a Scramjet (Supersonic Combustion Ramjet) combustor and its flame holding capability by solving Two-Dimensional full Navier-Stokes equations. The main flow is air entering through a finite width of inlet and gaseous hydrogen is injected perpendicularly from the side wall. An explicit Harten-Yee Non-MUSCL Modified-flux-type TVD scheme has been used to solve the system of equations, and a zero-equation algebraic turbulence model to calculate the eddy viscosity coefficient. In this study the enhancement of mixing and good flame holding capability of a supersonic combustor have been investigated by varying the distance of injector position from left boundary keeping constant the backward-facing step height and other calculation parameters. The results show that the configuration for small distance of injector position has high mixing efficiency but the upstream recirculation can not evolved properly which is an important factor for flame holding capability. On the other hand, the configuration for very long distance has lower mixing efficiency due to lower gradient of hydrogen mass concentration on the top of injector caused by the expansion of side jet in both upstream and downstream of injector. For moderate distance of injector position, large and elongated upstream recirculation can evolve which might be activated as a good flame holder.