汽车覆盖件拉延工艺补充面优化设计

分析了汽车覆盖件拉延工艺补充面截面线参数化特征，提出了工艺补充面优化设计准则，在UG平台上开发了覆盖件拉延工艺补充面优化设计模块，提高了覆盖件拉延工艺设计效率。     

基于虚拟仪器技术的自动化整合测试系统设计

应用虚拟仪器技术，通过GPIB总线将测试设备进行组合，实现测试的整合和自动化。通过软件设计，测试系统读取测试数据进行处理，以电子表格文件格式保存到硬盘，并可依设定的规格参数对产品是否合格进行自动判定；利用Lab VIEW Remote Panels技术，实现了测试系统的远程控制和数据共享。     

Compound Shear-Flexural Capacity of Reinforced Concrete–Topped Precast Prestressed Bridge Decks

Modern concrete bridge decks commonly consist of stay-in-place (SIP) precast panels seated on precast concrete beams and topped with cast-in-place (CIP) reinforced concrete. Such composite bridge decks have been experimentally tested by various researchers to assess structural performance. However, a failure theory that describes the failure mechanism and accurately predicts the corresponding load has not been previously derived. When monotonically increasing patch loads are applied, delamination occurs between the CIP concrete and SIP panels, with a compound shear-flexure mechanism resulting. An additive model of flexural yield line failure in the lower SIP precast prestressed panels and punching shear in the upper CIP-reinforced concrete portion of the deck system is derived. Analyses are compared to full-scale experimental results of a tandem wheel load straddling adjacent SIP panels and a trailing wheel load on a single panel. Alone, both yield line and punching-shear theories gave poor predictions of the observed failure load; however, the proposed compound shear-flexure failure mechanism load capacities are within 2% accuracy of the experimentally observed loads. Better estimation using the proposed theory of composite SIP-CIP deck system capacities will aid in improving the design efficiency of these systems.     

粘结薄板构件界面应力的有限元法预测

在外表面粘结纤维增强复合板材或钢板能提高钢筋混凝土、金属、木构件的强度或刚度。板材与被加固构件之间的剥离是常出现的破坏模式,而剥离主要取决于构件和薄板之间粘结层的界面应力。采用有限元分析法对界面应力进行预测,研究主要聚焦在非均匀分布荷载的简支梁。基于对梁、粘结层、板的不同假设,采用5个不同的有限元模型对界面应力进行描述。将5种方法的预测值进行相互对比,并与不同组合水平下的解析解进行对比。比较结果清楚显示了每个假设对所预测的界面应力的影响。对于复杂的粘接薄板构件,梁-弹簧-梁模型可以简单、精确地预测界面应力和剥离破坏。为说明梁-弹簧-梁模型的通用性,用相同的模型得到两个更复杂构件的界面应力并进行讨论。     

真空绝热板在节能领域的应用

真空绝热板是一种新型高效节能绝热材料,具有节能和环保的双重优点。主要应用于冰箱冰柜、冷链物流、医用及科研低温设施,自动贩售机、保温型热水器等具有保温保冷需求的行业。也可用于建筑围护或热工设备、阻抗热流传递的材料或材料复合体。真空绝热板在未来几年随着全球经济的逐步回暖以及节能环保的需要,市场的需求将越来越大。     

Methodology research on solving non-steady state radiation heat transfer in the room with Ceiling Radiant Cooling Panels

Long wave radiation heat transfer is the dominant cooling mode of the Ceiling Radiant Cooling Panels (CRCP). This unique cooling mode makes the calculation of indoor long wave radiation heat transfer extremely important. Actually, indoor radiation heat transfer is usually under non-steady state conditions. General calculation methodology (simplifying radiation heat transfer or using the equivalent network method of steady state) is complex and less accurate when solving this kind of problem. In addition, general methodology fails to solve the situation that the temperatures of some interior surfaces are lacking but the heat flows are known. This paper provides a calculation methodology improving the Gebhart method for modeling the non-steady state radiation heat transfer between indoor surfaces. Given parameter variations (temperature and net radiant heat flow) of the surfaces are transformed into discrete column vectors of unit time, and then matrix equations are established, which can greatly reduce the work. This methodology has been verified experimentally, which can be regarded as a theoretical basis for solving indoor non-steady state radiation heat transfer of CRCP systems.     

Industrialized Building Systems Construction in Malaysia

Available literature indicates that considerable research efforts have been directed toward the “hardware elements” of the industrialized building systems technology. However, the hardware elements are only concerned with the structure itself. Nonetheless, to date, the “software elements” of the industrialized building systems, which are concerned with the data and information available on the system, users, clients, establishment of manufacturing and assembly layout and process, as well as allocation or resources and material, have received little attention. There is therefore a dire need to overcome the shortage in the software elements of the building system research. This paper reports a survey conducted on industrialized building system construction companies. The main objective is to present the building system technologies existing in Malaysia and to examine problems and constraints associated with these technologies.     

电镀镍金板生产中金面变色改善分析

PCB电镀镍金生产过程中有时会发生金面变色的问题,金是稳定的金属元素,理论上金的氧化并非自发,分析认为出现三种情况会导致金面变色。本篇将从导致变色的生产流程重要环节上加以探讨分析。     

Static and Cyclic Racking Performance of Autoclaved Aerated Concrete Cladding Panels

Laboratory experiments subjected full-scale autoclaved aerated concrete (AAC) cladding panel specimens to static monotonic loading and incrementally increased displacement amplitudes of cyclic racking movements. The objective of the study was to characterize the seismic performance of cladding panel walls made up of the newly introduced AAC in the U.S. market. The study found that conventional connectors used to attach AAC cladding panels to structural systems have not been designed for in-plane seismic resistance and would need to be redesigned in order to safely satisfy building code’s allowable drift.     

Validity of SDOF Models for Analyzing Two-Way Reinforced Concrete Panels under Blast Loading

The combined manual TM 5-1300/NAVFAC P-397/AFR 88-22, Structures to Resist the Effects of Accidental Explosions, published by the joint departments of the Army, the Navy, and the Air Force, has been used in all NATO countries for the past 50 years for protective design applications. The manual was recently reformatted to meet the Department of Defense Unified Facility Criteria (UFC). As a first step, the current production of the new document, UFC 3-340-02, focused on making the original TM 5-1300 available in a more functional format so that future technical updates can be facilitated. In this study, a single-degree-of-freedom (SDOF) model, based on the guidelines of the UFC 3-340-02, was used to formulate a FORTRAN code to predict the response of SDOF systems under blast. The code was used to generate pressure-impulse (P-I) diagrams for a series of two-way reinforced concrete (RC) panels with different dimensions, aspect and reinforcement ratios, and support conditions. The P-I diagram predictions were compared to the results of experimentally validated nonlinear explicit finite-element (FE) analyses and significant differences in deflection and shear predictions were observed. The general trend of results and the major characteristics of the P-I diagrams were discussed in terms of the discrepancies between the SDOF and the FE predictions. The work presented in this paper is expected to contribute to improving the modeling provisions of the two-way RC panels in the future edition of the UFC 3-340-02 by understanding the limitations of SDOF models using advanced FE analysis techniques.