机械结构模态参数时域识别方法原理及展望

分析了传统模态分析方法在大型机械结构模态识别中的弊端,指出利用基于响应信号的时域信号进行大型机械结构的模态参数识别已日益成为一种趋势。对时域模态参数识别的主要方法进行了论述,分析了各类方法的识别原理及优缺点,在此基础上总结了目前时域识别方法存在的问题,并对今后的研究工作进行了展望。国家自然科学基金资助项目(编号:50855002

大长径比筒形透明注塑件浇口设计与优化

分析了典型大长径比筒形透明注塑件—PMMA握把结构的工艺特点,设计了中心进胶爪形浇口,并利用Moldflow软件对其尺寸进行了优化分析,解决了此类塑件常出现的熔接痕、偏心等缺陷,为此类产品的模具设计提供了典型例证

F-SAE赛车后悬架优化分析

运用多体动力学软件AdAMS/VIEW模块建立f-SAE赛车后悬架模型,并对模型进行仿真分析,研究分析fSAE赛车运动中后悬架随车轮上下跳动时定位参数的变化规律,评价悬架数据合理性。采用优化分析对悬架不合理数据进行优化,进一步改善悬架系统性能,以提高产品开发质量

Crash compatibility of a light truck vehicle to a passenger car: The relationship between delta velocity and occupant injury severity

研究了真实世界事故中、侧面冲击载荷作用下轻型卡车与轿车驾乘人员的损伤位置分布。采用了美国国家汽车取样系统/耐撞性数据库(nASS/CdS)近136万个碰撞兼容性案例,将所有驾乘人员损伤等级分为MAIS0-7和MAIS3+两种情况,在不同速度下,以涉案撞击车和被撞击车在碰撞前后的速度变化值为变量,分析了乘员不同损伤部位(头部/面部/颈部、胸部、骨盆、上肢和下肢)的损伤分布。结果表明:撞击车乘员受损速度区间比被撞击车偏大,乘员损伤风险偏低。因此,从碰撞兼容性角度考虑,减少驾乘人员的骨盆损伤,可以减少所有涉案乘员损伤风险机率。This paper analyzes the distribution of injured occupants in side impact collisions of light truck vehicles to passenger cars in the real world.The injury levels were divided into MAIS 0-7 injured occupants and MAIS 3+ injured occupants.The injury distribution of five main seriously injured body regions (including head/face/neck, chest, pelvis, upper extremity and lower extremity) was investigated at delta velocity before and after crash, using the delta velocity of struck and striking vehicles as the variable, according to 1.36 million weighted crash compatibility cases extracted from the US National Automotive Sampling System (NASS) / Crashworthiness Data System (CDS) database.The results show that the delta velocity of striking vehicle is larger than that of the struck vehicle, and the occupant injured risk ratio is lower than that of the struck vehicle.Therefore, avoiding the pelvis injury of drivers and passengers can reduce the risk of total occupants involved in the collisions in consideration of crash compatibility.厦门理工学院科技研究项目(JKY10023R);福建省教育厅科技项目(JA11239

Study on Turbocharger Rotor Axial Thrust Test in Start and Stop Process

涡轮增压器起动和停机过程转子所受的轴向力大小对于增压器的设计是至关重要的。以JP60C型涡轮增压器为研究对象,利用有限元方法计算增压器止推轴承的应变场,确定了转子轴向力的测量方案。并在增压器性能试验台上对增压器转子轴向力进行实验测量。实验结果表明,增压器起动和停机时,止推轴承所承受的轴向力远大于稳定工作时所承受的轴向力;且起动和停机工况下,转子所受的轴向力方向相反。试验结果将为增压器止推轴承的合理设计提供理论依据。One of the most challenging aspects in turbocharger design is the axial thrust acting on the rotor in start-stop conditions.JP60C turbocharger was taken as an example for researching.The distribution of strain in axial thrust is calculated using finite element method.Based on the result of calculation,the measuring strategy of axial thrust is determined,and the axial thrust was measured on turbocharger test rig.The testing results show that the value of axial trust in the start-stop conditions is much bigger than that under stable conditions.The direction of axial thrust bearing on the rotor in start condition is opposite to stop condition.The testing results would provide theoretical reference for thrust bearing reasonable designing of the turbocharger

应用型本科高校人才培养的特色化研究——以厦门理工学院“亲产业”大学办学实践为例

应用型本科高校人才培养要基于应用型本科高校发展的合理定位,并在人才培养的全过程中力行特色化培养理念,还要有与之相呼应的质量管理机制予以保障应用型本科高校人才培养的特色化发展。厦门理工学院坚持“以生为本,服务产业,培养海西一流亲产业应用型人才“的办学思路,着力优化专业结构布局,使“专业链“紧密亲和“产业链“;实施“教学卓越工程“并采取一系列质量保障措施,培养亲产业应用型人才。这一办学实践是对应用型本科高校人才培养的特色化发展的探索。福建省社科项目“应用型本科人才培养质量研究”(项目编号:2011B241)的研究成果之

Design and verification on air inflow correction system of FSAE engine

针对限制器引起的进气管内压力损失会增加赛车实际油耗的问题,该文以单缸四冲程赛车发动机为研究对象,从混合气体空燃比控制、喷油量的控制和进气量测量3个方面分析了电喷系统,结合电喷系统的特点建立了进气量修正方案,在此基础进行了控制单元的硬件和软件设计。通过对发动机喷油脉宽的检测验证了进气量修正控制单元满足设计要求,达到了降低油耗、提高赛车竞争力的目的。In view of that the pressure loss in the air inflow pipe caused by the resrtictor makes the actual fuel consumption relatively increaseing,the four-stroke engine of the formula SAE car is investigated here.The electronic fuel injection(EFI) system is analyzed from three aspects of the air-fuel ratio control of the mixed gas,the control of fuel injection quantity,and the measurement of air inflow.According to the characteristics of the EFI system,the air inflow correction scheme is designed, and the hardware and software of the control unit are accomplished.The test of pulse-width of EFI system shows that the control unit of air inflow correction can meet the design requirements,reduce the fuel consumption,and improve the competitiveness of the FSAE.国家自然科学基金(51305372

新型精密模具表面镜面加工技术

介绍了混粉电火花与大面积脉冲电子束模具镜面加工(EBM)技术的概况,对两种技术在加工材料、加工效率、加工成本及表面质量等进行分析对比,指出两种加工技术的应用特点。为精密模具表面镜面加工提供了技术指导

A Study of Graphics Storage and Re-drawing Technology

分析了AuTOCAd本身提供的图形实体保存与绘制技术存在的不足,提出基于ObJECTArX MfC与ACCESS数据交互技术的图形实体保存与绘制新方式,图形实体数据保存到独立于AuTOCAd图形库的ACCESS数据库中,实现了复杂图形实体的永久性保存和跨工程图文件的使用,应用于模具设计等案例重用过程中,效率显著提高The shortages in the graphic storage and drawing function of AutoCAD are analyzed.Based on the data exchange between ObjectARX MFC and Access,a new method is proposed that graphic entities data can be saved in Access independent of AutoCAD.Therefore,the permanent storage of complex graphic entities and the use beyond engineering drawing files are realized.Application of mold design shows that the efficiency can be enhanced greatly.国家自然科学基金资助项目(50843059);福建省科技计划资助项目(2007F5095

Study on Highway Road Detection Based on Computer Vision

根据高速公路路面的基本特征,通过分道线特征点投影位置的计算,提取出了比较完整的当前车道分道线特征点。建立道路边缘灰度模型,采用gAbOr变换多分辨率的特点,对图像按方向进行滤波处理,实现道路边缘线检测和拟合。实验结果表明,所讨论的方法在工程实践中有实际应用价值。According to the basic characteristics of the road and through marginal extraction,the location of current lane line can be acquired.After calculating projection location of the lane feature points,feature points of a relatively complete current lane dividers can be distilled.Establishing the model of road edge grey scale and adopting the multi-resolution characteristics of Gabor transform,they can filter the image so that they can realize the detection and fitting of the road edge line.Experimental results show us that the method discussed in this text has a certain value in practice.福建省青年科技人才创新项目(2006F3121