现浇泡沫轻质土在挡墙台后的应用

本文通过某高速互通匝道路基挡土墙台后采用现浇泡沫轻质土填筑的工程实例,介绍了挡土墙抗滑移稳定性不足的情况下的病害处理,以及一种新型的轻质材料现浇轻质泡沫土的应用和施工。     

基于碰撞安全的复合材料尾门设计

由于环保和节能的需要,汽车轻量化已经成为世界汽车发展的潮流。介绍了复合材料的优缺点,并将复合材料应用到汽车尾门,通过材料选型、结构设计以及碰撞安全的CAE仿真分析,设计出后部碰撞性能与传统钣金尾门性能相当的复合材料尾门,最终轻量化比例达到35.3%。     

基于参数化方法的圆碟形水下滑翔机结构轻量化设计

圆碟形水下滑翔机结构质量大小对其性能影响较大。为提高圆碟形水下滑翔机结构分析效率,在圆碟形水下滑翔机耐压壳结构分析的基础上,对圆碟形耐压壳结构进行参数化设计及优化研究。运用ANSYS参数化设计语言APDL对圆碟形耐压壳进行参数化建模与分析,采用零阶与一阶相结合的优化方法,对圆碟形水下滑翔机耐压壳结构进行轻量化设计。结果表明,参数化分析方法有效地提高了分析效率,优化后所得最优解与初始值相比,质量减轻了29.4%,圆碟形水下耐压壳轻量化效果明显。     

泡沫胶凝法制备轻质钙长石耐火材料的工艺研究

以煅烧矾土、煅烧高岭土、硅灰石、蛋白质发泡剂、明胶、聚乙烯醇、硅溶胶和聚合硫酸铝为原料,采用泡沫胶凝法制备了轻质钙长石材料,主要研究了蛋白质发泡剂加入量、明胶加入量、硅溶胶和聚合硫酸铝的加入时机以及硅溶胶加入量等对泡沫胶凝成型工艺的影响,并分析了烧成后轻质钙长石材料的物相组成、显微结构和性能。结果表明:1)蛋白质发泡剂-水泡沫体系中蛋白质发泡剂的体积分数为15%时,体系的发泡倍数达到最大;每100 mL蛋白质发泡剂-水泡沫体系中加入1.2 g明胶时,泡沫的沉陷率最小,稳定性最好;将聚合硫酸铝促凝剂分散到黏稠泥浆中,制成泡沫泥浆后,在高速搅拌下按1 L泡沫泥浆加入137 mL硅溶胶的比例缓缓加入硅溶胶,搅拌结束15 m in后体系发生胶凝。2)按试验确定的最佳工艺成型并于1 280℃保温0.5 h烧成后的轻质钙长石材料,以钙长石为主晶相,并有少量刚玉相;烧成后的轻质钙长石材料为多孔结构,其气孔多为封闭气孔,且分布较均匀,平均孔径约200μm;烧成后的轻质钙长石材料的性能参数已达到,有的甚至已超过德国的Jm23砖。     

Upgrading Computational Design

Shajay Bhooshan heads up the computation and design ZHACODE group at Zaha Hadid Architects (ZHA) and is a course master at the Architectural Association Design Research Laboratory (AADRL). Here he argues that Parametricism 2.0 has a vital role to play in the progressing of computational design. Assimilating the exploratory developments of the last 15 years, he asserts how the next phase of Parametricism will enable a further consolidation and evolution of digital practices.     

应用正交试验法汽车B柱轻量化设计分析

B柱是车身重要的承载结构件,对侧面碰撞安全具有重要影响,同时B柱也是轻量化设计的重要单元。根据B柱的结构特点和在车辆侧面碰撞中的结构形态,搭建B柱侧面碰撞仿真分析模型;根据分析结果和零件的可制造性分析,基于正交试验法对B柱的材料和厚度进行设计,并根据乘员的相对位置对激光拼焊的焊缝进行设计;根据侧面碰撞的侵入量和侵入速度对比,选出最优激光拼焊设计方案;基于侧面碰撞分析模型,对轻量化设计前后B柱的安全性进行对比分析。结果可知:随拼焊线向底部移动,危险区域的最大减薄率并不是线性增减,在可选取范围内将焊缝位置确定为距离底端380mm的位置;B柱选择拼焊板结构,下部材料为DP780,厚度为1.8mm,上部材料为DP590,厚度为1.6mm;采用激光拼焊结构的B柱重量减轻23.1%,各位置测量点的侵入量最高减少18.6%(D4位置),满足结构耐撞性的要求。     

Data-based spatial feedforward for over-actuated motion systems

For advanced motion systems there is an increasing demand for higher production throughput and accuracy. Traditionally, such systems are designed using a rigid-body design paradigm, which aims at designs with high stiffness. The alternative is to design a lightweight system and deal with the resulting flexibilities by over-actuation and over-sensing. This paper presents a data-based spatial feedforward method based on previous task trials, which aims at reducing the vibrations over the complete structure during motion. The proposed method is experimentally validated on an industrial prototype and compared to standard mass feedforward using rigid-body decoupling.     

Lightweight Concrete Using Local Industrial By-product

Construction is one of the largest users of energy, material resources and water and it is a formidable polluter. One of the major materials used in construction is concrete and ordinary concrete contains about 12% cement which is a major producer of greenhouse gas in the world. The use of waste materials as partial replacement of cement in concrete reduces greenhouse gases, frees up land fill space, and reduces raw materials consumption. This contributes towards sustainable development, as in a sustainable society, nature is not subject to systematically increasing concentrations of substances extracted from the earth＇s crust. This research work explores the possibility of replacing some percentage of cement in concrete with marble sludge powder to produce lightweight concrete. This was achieved by determining the compressive strength and some hardened properties of concrete like sorptivity and carbonation with marble sludge. The results so far have been able to prove that lightweight concrete can be produced when some percentage of cement is replaced with this waste.