Sensitivity analysis of a motorcycle frame using the Monte Carlo method

Sensitivity analysis of motorcycle frames is useful for improving the design success rate. Based on sensitivity analysis theory and using the Monte Carlo and numerical simulation methods, a new 250 type integral motorcycle model was built and dynamic sensitivity analysis conducted. Sensitive design parameters that have great influence on frame vibration were discovered. By modifying the values of sensitive design parameters, the vibration of some measuring points was reduced. This reduction shows that the sensitivity analysis method is reliable and practical, and it can be used in sensitivity analyses of other complicated structures.     

Structural optimization design of the electric motorcycle frame

In order to analyze the performance of the electric motorcycle frame structure under working condition of vibration and reduce its weight,the transient finite element analysis model is developed with the theory of transient dynamics,and frame dynamic strength is calculated to obtain the maximum stress and stress distribution of frame under the working condition. On that basis,we establish the optimum model with the target function of the frame’s weight based on the optimal module of Hyperworks,and make optimization design of the frame under intensity and rigidity constraint conditions. The theory analysis and experimental results indicate that the frame has surplus strength and the value of safety factor is high under working condition of vibration ,and the strength of the optimized frame meets the requirements of safety and manufacturing process,meanwhile,the weight of frame is reduced by 12.1%,which shows that the optimization method is reliable and effective for the design of the structure of the frame.     

Application of sequential response surface method tothin wall beam lightweight design

It is proposed to introduce approximate model method to crashworthiness optimization design of thin wall beam,and the approximate model can be optimized by using sequential response surface method.In order to solve the parameterization design problem of finite element model,a parameterization model about material,cross section size and spotweld of thin wall beam is established by developing corresponding procedures.The results show that optimization design can not only improve the performance of absorbing energy of thin wall beam,but also reduce the weight greatly;the approximate model method can greatly improve optimization efficiency.     

A fault data recording system design for hybrid electric vehicles

A data recording system for fault diagnosis of hybrid electric vehicles was studied by taking the integrated starter and generator (ISG) hybrid electric vehicle as the investigation object. The fault diagnosis communication net was established using a CAN bus and a K line. As designed, the system hardware structure included a CPU processing module, a communication module, and a USB recording module. With the system requirements and characteristics in mind, special circuit design and analysis of USB mass storage module were carried out based on the hardware scheme and software design. In the running test, the fault data recording system worked stably, and the data was recorded integrally and correctly. At the same time, the online display data accurately reflected the vehicle's running status.     

RC加气混凝土砌块组合墙加固框架抗震性能试验研究

RC加气混凝土砌块组合墙（简称组合墙）是由混凝土梁柱网格与加气混凝土砌块组合形成的一种轻型网格式抗震墙,可用于框架结构的抗震加固。笔者进行了1/2比例空框架试件、组合墙试件和组合墙加固框架试件的低周反复荷载试验,分析了各试件的主要破坏过程,对比了组合墙加固框架前后试件承载能力、刚度等抗震性能变化。试验结果及分析表明：组合墙加固框架后承载力、抗侧刚度有较大幅度提高,中大震及大震阶段其承载力、等效刚度约为空框架和组合墙单独受力之和的0.9倍,两者具有良好的协同工作性能;加固试件的破坏过程基本上遵循填充砌块混凝土框格外框架的破坏顺序,能够发挥组合墙多重抗震防线的特点,采用RC加气混凝土砌块组合墙加固框架是一种较为经济实用的加固方法。     

The cooling structure of Ni MH batteries in hybrid electric vehicles

Focusing on Ni MH batteries used in hybrid electric vehicles (HEV), a simulation analysis of the flow and temperature fields of the cooling structure in existing batteries is carried out using computational fluid dynamics software. The results show that the temperature uniformity is poor. The uniformity of the flow and the temperature fields is improved by adjusting the baffle and battery positions, changing the tilt angle and the distance between the batteries, inserting wind plates and a coating insulation layer. The coating insulation layer achieves the best effect. Further simulation shows that the coating insulation layer method has the best effects. The results provide the design basis for thermal management program of Ni MH batteries in HEV.     

The Finite Element Back Dealing and Object Design of Complex Joist frame Structuer

A simulation design method of the finite element analysis was described using object oriented programs.A data management class TSTRUCT of the large joist structure was also defined.     

Relationship between curvature ductility of column and structural displacement ductility for concrete frame structures

Based on the domestic experimental data of multi-storey concrete frame structures, the relationship between curvature ductility of concrete frame column and structural displacement ductility is proposed. 32 sets experimental data of system displacement ductility and the corresponding storey displacement ductility, which are mainly obtained from beam hinge yield mechanism and failure mechanism, are collected, and statistical property of system placement ductility is analyzed. Curvature ductility of concrete frame column is derived from storey displacement ductility factor by the classical analytic solution, and relationship between curvature ductility of frame column and structural displacement ductility is established. Correlation coefficient (R) for fitting power exponent function model and sample test data is 0.775. Results of nonlinear numerical analysis examples show that statistical function model is able to direct the ductility control design of concrete frame column.     

Improved algorithms of modal parameter identification and its application to shaking table frame model test

Based on the data-driven stochastic subspace identification (SSI), an improved ITD method, an improved STD method and an improved complex index method are put forward. SSI has high identification accuracy, and Hankel matrix orthogonal projection calculation of data can retain all the useful information in the original data and simultaneously remove noise. The data obtained in P-matrix is taken as input for the ITD , STD and complex index methods, and then the three methods would no longer need random decrement technique or NExt method for pre-processing, thereby eliminating the error caused by the two pretreatment methods.The improved methods are applied to the modal parameter identification for structure shaking table test model by using the simulated earthquake response data from Tongji University. The recognition results further prove the correctness and feasibility of the improved methods.     

大跨度PC连续刚构桥徐变预测模型

为了能准确预测混凝土收缩徐变,提出了一系列徐变预测模型,但传统的徐变理论研究主要是针对普通混凝土进行的,所提出的徐变模型并不能完全适用于高强混凝土。对各徐变预测模型进行分析比较,最终参考了日本混凝土示方书建议模型,并在高强混凝土徐变试验的基础上,提出了一个适用于高强混凝土的徐变预测模型。基于Abaqus平台,使用Python语言进行二次开发,定义了修正模型的徐变规律,并采用修正后的模型计算牛角坪大桥的徐变应变。结果表明,修正模型的精度,能很好的满足工程需求。     

forming process planning and technology realization of the monoblock break beam frame

In order to meet the performance demands of train lorry, a die forging drawing method based on structure features analysis was proposed to form the L A break beam frame. The finite element method was used to simulate a series of die forging processes and the drawing processes with different parameters. The optimum cross section shape of the performing die was obtained from these simulation results. It is found that local back flow of the metal is the primary cause of necking defects in drawing. Furthermore, the best drawing speed is determined to be from 87 mm/s to 96 mm/s. The results of trial manufacturing and product detection indicate that employing a die forging drawing process to form the monobloc break beam frame is feasible.     

地震下高墩刚构桥桥台背土相互作用分析方法对比

针对重力式U型桥台背土相互作用,结合现行抗震规范,提出了4种分析模型及其力学本构关系和计算式。采用非线性时程法对比研究了某在建高墩双薄壁连续刚构桥的桥台背土相互作用效应。结果表明：只有弹簧模型可以求得与精细模型基本一致的高阶弹性模态;在纵桥向,滚轴模型和支座模型的结果都比精细模型小,弹簧模型相对精细模型的计算误差最小,关键内力误差不超过20%;在横桥向,支座模型的内力最接近精细模型,而弹簧模型和滚轴模型的结果都偏保守;桥台刚度对关键地震内力的影响幅度低于10%,而桥台有效参与质量的影响幅度也低于15%。综合考虑分析精度和计算成本,弹簧模型在抗震设计中更值得推荐。     

Structure design and fabrication for resonant accelerometer based on electrostatic stiffness

The introduced resonant accelerometer makes use of the equivalent electrostatic stiffness to sense the acceleration. The sensitivity can be adjusted by changing the applied sensing voltage and it is robust for the fabrication error. According to the sensing principle,the dynamic model of the single beam accelerometer is built along with the no-linear relationship of the output frequency and the displacement of all positive components. When the stiffness of the vibrating beam is much bigger than the stiffness of the fold beam, the sensitivity can effective achieve. It is the restriction for the structure design. For the differential structure, mode analysis shows it is a lower mode in plane for the work mode. Decreasing the stiffness of connected end for the double vibrating beam can reduce the disturbance error. The bulk micromachining for the resonant accelerometer can achieve high depth width ration etching. The experiment find the structure is not broken and there is the same frequency disturbance problem. FM is suggested to deal with the disturbance. Theory analysis and test provides some important conclusions for the design of the novel type resonant accelerometer.     

design of a closed loop control virtual test for vehicle handling stability

In an effort to address the high risks and qualification demands of test drivers, a vehicle model and a driver model were built based on ADAMS/CAR, an advanced block of ADAMS. The steering efforts test procedure was designed according to the national standard GB/T 6223.5—1994. A virtual test was performed in ADAMS, and the results calculated. The results show that the driver model possesses a strong capacity to charge the vehicle model. The virtual test results satisfy the evaluation index, indicating the virtual test can be used to test and improve vehicle performance.     

Automatic control strategy and its test analysis for the heavy truck AMT

By analyzing the startup process of automated mechanical transmission(AMT), fuzzy control algorithm of clutch engagement speed and constant engine speed in part during startup are proposed based on comprehensive consideration of driver’s startup intention and startup performance indices. Through dividing shift process of AMT into seven stages, clutch control logic and goal speed control algorithm of engine during the shift process are put forward. Aiming at the emergency braking condition, a control strategy of jump downshift during braking and a determination method of target gear are also proposed. In order to verify the validity of control strategy, an AMT prototype vehicle is developed and the test of startup, shift and jump downshift are carried out.     

河道淤泥气泡混合土微观构造及力学性质相关性

基于河道淤泥气泡混合土(FMLSS)的微观构造特征,通过微观构造观察和分析,评价了FMLSS的强度特性和破坏机理。试验结果表明,保持FMLSS含水量一定,随着气泡掺入量的增加,FMLSS的内部平均等效孔径和气孔面积百分比含量呈线性增大趋势、而随着水泥掺入量的增加呈减小趋势;随着气泡掺入量的增加,FMLSS的气孔大小分布的均匀性降低,气孔平均等效孔径增大。试验结果还表明,FMLSS的强度发挥及破坏机理与FMLSS的气孔分布的均匀性以及等效孔径等微观构造参数存在明显的相关性。     

Analytic Method for the Free Vibration of Plane Frame Structure

The analytic method for the free vibration of plane frame structure is presented. It is achieved by transforming the general eigenvalue problem of natural frequency and vibration mode of continuously distributed property system into typical boundary value problem of ordinary differential equation (ODE). A series of ODE, corresponding to the general eigenvalue problem, is formed, and then is solved by an general ordinary differential equation solver-COLSYS. Each component of a frame structure is regarded as an element in the analytic method. This makes it more efficient than that of finite element method which needs to increase elements to get the value of high-class natural frequency and vibration mode accurately. Some applications of the method show that it can solve the free bending vibration of plane-frame structure with various types of displacement constraint. The result indicates that this method is precise and efficient.     

Calculation Methods for Steel Frame Structure Based on the Structural Ultimate Bearing Capacity

The existing problems in calculation approach for multi-story and high-rise steel frame structure are summarized. As the shearing deformation is considered, the analysis methods for steel frame structure are put forward based on the structural ultimate bearing capacity, which is on the basis of second order inelasticity analysis for steel structure. In the approach, the tangent module brought forward by Bleich, F. is used, the second-order refined plastic hinge method presented by Liew, J. Y. R. is modified.     

对偶性与特大增量步算法在复杂平面框架中的应用

特大增量步算法（LIM）是一种基于力法和广义逆矩阵理论的迭代算法,在简单桁架和刚架非线性初步应用中,达到相同计算精度下有同等甚至超过位移有限元的计算效率。针对工程中的复杂杆系结构,利用平衡与协调的对偶性,探讨LIM在复杂平面框架结构中的应用,建立了平面框架结构的LIM基本方程,提出了针对典型支座约束以及组合结点的处理方法。该处理方法的线弹性问题算例表明,与位移有限元相比具有至少同等的精度和相当的计算效率。在支座本身不考虑塑性的情况下,该处理方法同样适用于弹塑性问题,为LIM在复杂杆系结构的弹塑性分析中奠定了基础。     

Calibration of Seismic Provisions for RC Frame in Different Earthquake-Intensity Regions in China

With examples of three 6-storey RC frames by using an elasto-plastic dynamic analysis program PL-AFJD of plane frame, developed by the second author of this paper, the frames designed for different earthquake-intensity regions (intensity category 7, 8, 9 respectively) are analyzed nonlinearly under four ground motions at the action of rare earthquake. Three frames strictly conform to the National Standard GBJ10-89 and the dimensions of columns are changed once along the height. The structure designed on intensity category 7 shows a relatively small response, which could be sustained by the structure. Though the hinge formation in columns can not be prevented, the inelastic deformation of columns is not serious, the structure at intensity category 9 exhibits a relative strong response, but the deformation of most columns is within the capacity and the trend to form a soft-storey does not appear. It is the structure at intensity category 8 that shows a severe response. Though the visible soft-storey can not be found, the deformation of some columns is beyond the capacity of inelastic hysteretic deformation under certain inputs, which indicate the possibility of local collapse.The elementary analysis results demonstrate the different effectiveness of seismic provisions for three different earthquake-intensity regions, which may be a reference to the amendment of National Design Standard.