基于一种新拓扑图方法的n杆阿苏尔杆组的构型综合与分析

简要论述了目前杆组法在型综合和机构分析方面的现状,计算分析了杆组的特征值,提出了一种新的机构拓扑图表达方法和绘制规则,基于该规则可快速、准确地对全转副6杆、8杆组进行型综合,并给出了全部构型拓扑图。在此基础上给出了基于杆组结构特征的构型数组表示方法,通过一个实例利用上述方法对机构变换进行了分析。     

注塑机合模机构拉杆螺纹的有限元分析

拉杆是合模机构中最为关键的部件,借助于Pro/E和Hyperworks建立抱闸机构的非线性接触有限元模型。在Ansys中进行结果分析,确定了7500 kN锁模力作用下最大的应力-应变区域,识别薄弱环节,为拉杆螺纹的结构改进设计和工程实践提供理论依据。     

国产加工中心故障模式及影响分析(FMEA)

应用FMEA法对国产VMC系列加工中心进行故障分析.查清整机各故障部位、故障模式的比率,找到可靠性薄弱环节,并把故障分析的结果反馈给设计、制造、装配等部门,从各方面采取措施,明显提高了VMC加工中心产品的可靠性水平.     

偏心支撑钢框架延性抗震设计探讨

偏心支撑钢框架结构体系是一种非常适合强震地区的抗震结构体系.国内外许多高层建筑采用了该结构体系,尤其在美国与日本的高地震烈度地区.国内外现行规范对该体系的设计均未能充分体现其良好的延性与耗能能力,但只有通过结构的延性设计才能使结构真正具有耗能能力.本文从不同支撑类型的刚度、高跨比、延性和双重体系探讨了支撑类型的选择与布置形式,分析了耗能梁长度与截面设计以及耗能梁与支撑、柱的连接形式对偏心支撑钢框架结构体系延性和耗能能力的影响,提出了偏心支撑钢框架结构体系延性抗震设计的建议与思路,为规范修订和工程应用提供一些参考.     

《先进制造工程学》博士生特色课程建设的探索与实践

本文针对机械工程一级学科博士生在选题、中期筛选等培养环节中暴露出来的知识面窄、科研视野不开阔等问题,依托学院在二级学科研究与教学上的总体优势,实践并探索性地将学院多名博士生导师研究内容综合在一起,联合开设反映机械工程一级学科最新成就、最新进展和最新动态的系列研讨课讲座,并构建为一门新的《先进制造工程学》博士生课程。通过学院多年来对该课程的教学实践,证明该课程对学生专业领域创新思维培养的效果是显著的,课程设置思路及体系是值得借鉴的。     

匠心汇聚书“五缘”——记中国闽台缘博物馆室内外环境设计

该文通过以中国闽台缘博物馆室内外环境设计为例,探讨设计如何表现闽台两岸建筑特色,传达"五缘"文化诉求,在运用现代技术材料、营造现代空间、满足现代功能的同时恰当合理地融入地域建筑文化。     

Study of a new type of steel slit shear wall with initially twisted links

To address the issue of strength and stiffness degradation of steel slit shear walls (SSSWs) after the occurrence of out‐of‐plane buckling at large lateral deformation, a new type of SSSW made by assembling initially twisted steel plate links is proposed in the present work. Three types of SSSW specimens, with vertical slits, narrow rhomboid openings, and initially twisted steel plate links, respectively, were manufactured and tested under quasi‐static cyclic loading. Test results showed that the SSSW assembled by initially twisted steel plate links had no strength degradation and a nearly constant positive second stiffness throughout the whole loading process with a maximum drift ratio of 6%, whereas the other two SSSW specimens exhibited obvious degradation of strength, stiffness and energy dissipation capacity. The new SSSW also had much smaller residual strength, and its deformation capacity was largely improved. The method to predict the elastic stiffness of the new SSSW was proposed, by which the predicted results agreed well with test results. A user‐defined macromodel was developed to simulate its force‐deformation hysteretic behavior.     

Healing Effect of Controlled Anti‐Electromigration on Conventional and High‐Tc Superconducting Nanowires

The electromigration process has the potential capability to move atoms one by one when properly controlled. It is therefore an appealing tool to tune the cross section of monoatomic compounds with ultimate resolution or, in the case of polyatomic compounds, to change the stoichiometry with the same atomic precision. As demonstrated here, a combination of electromigration and anti‐electromigration can be used to reversibly displace atoms with a high degree of control. This enables a fine adjustment of the superconducting properties of Al weak links, whereas in Nb the diffusion of atoms leads to a more irreversible process. In a superconductor with a complex unit cell (La_2?x Ce_x CuO₄), the electromigration process acts selectively on the oxygen atoms with no apparent modification of the structure. This allows to adjust the doping of this compound and switch from a superconducting to an insulating state in a nearly reversible fashion. In addition, the conditions needed to replace feedback controlled electromigration by a simpler technique of electropulsing are discussed. These findings have a direct practical application as a method to explore the dependence of the characteristic parameters on the exact oxygen content and pave the way for a reversible control of local properties of nanowires.     

Spatial distribution of water supply reliability and critical links of water supply to crucial water consumers under an earthquake

This paper describes a process to characterize spatial distribution of water supply reliability among various consumers in a water system and proposes methods to identify critical links of water supply to crucial water consumers under an earthquake. Probabilistic performance of water supply is reflected by the probability of satisfying consumers’ water demand, Damage Consequence Index (DCI) and Upgrade Benefit Index (UBI). The process is illustrated using a hypothetical water supply system, where direct Monte Carlo simulation is used for estimating the performance indices. The reliability of water supply to consumers varies spatially, depending on their respective locations in the system and system configuration. The UBI is adopted as a primary index in the identification of critical links for crucial water consumers. A pipe with a relatively large damage probability is likely to have a relatively large UBI, and hence, to be a critical link. The concept of efficient frontier is employed to identify critical links of water supply to crucial water consumers. It is found that a group of links that have the largest UBI individually do not necessarily have the largest group UBI, or be the group of critical links.