The busbar system for Wendelstein 7-X prepared for assembly and operational loads

Forschungszentrum Jülich has taken over the design, manufacturing and assembly of the superconducting busbar system for the stellarator Wendelstein 7-X. This includes the busbars itself, the support structure consisting of supports and clamps, and the joints for electrical and hydraulic connection of the busbars and coil terminals. Apart from providing the required electrical connection scheme, the busbar system has to be designed for relevant electrical and mechanical loads. Numerous interfaces and geometric boundary conditions define the confined space to accommodate the busbars and their support elements. This article describes how the individual challenges to engineering have been met in the course of the project. This includes design concepts and the method for iterative design of supports with respect to the individual load distribution caused by the supports itself.     

Surface Analysis of Chesapeake Bay Water Quality Response to Different Nutrient and Sediment Loads

Based on a set of Chesapeake Bay Estuarine Model (CBEM) scenarios, a three-dimensional response surface of a water quality index, such as chlorophyll concentration, versus a pair of loading constituents, e.g., nitrogen and phosphorus, is constructed. The responses of water quality, such as dissolved oxygen, chlorophyll, and water clarity, to nitrogen, phosphorus, and sediment loads are analyzed. From the response surface, a water quality response is estimated under loading conditions beyond that of a limited set of scenarios. Response surfaces may be used to determine the possible universe of nutrient and sediment load reductions needed to obtain a particular water quality standard and to examine the tradeoffs among nutrient and sediment load reductions that achieve the same water quality objective.     

内部爆炸加载条件下圆柱钢壳的动态断裂

在内部爆炸冲击波载荷作用下,爆炸容器的动态断裂是进行爆炸容器安全评估和失效分析的基础。为了研究爆炸容器的动态断裂特征,进行圆柱钢壳在中心装药的爆炸加载实验,采用非线性动力有限元分析程序LS-DYNA分析圆柱钢壳的弹塑性动力响应,研究圆柱钢壳的宏观变形和断口的宏观、细观形貌,分析圆柱钢壳的断裂模式及断裂机理。结果表明,圆柱钢壳纵向断口具有微孔聚集型剪切韧窝断裂特征,呈现出微孔聚集型剪切韧性断裂模式。内部爆炸冲击波加载下圆柱钢壳因径向膨胀发生动态塑性变形,产生剪切带,由于剪切带的软化效应而成为优先断裂通道,剪切带和环向拉应力的共同作用是形成微孔聚集型剪切韧窝断裂这种混合韧性断裂模式的原因。     

电铁牵引负荷对电网运行造成的影响及其解决措施

阐述电铁牵引供电系统的原理,分析电铁牵引负荷的特点,研究电铁负荷对电力系统运行的影响及对设备的危害,并从技术上和管理上提出解决措施。     

《传热学》教学改革实践与思考

《传热学》是建筑环境与设备工程学科核心基础课程之一。结合自身教学实践,建立了《传热学》理论教学的宏观知识体系,并结合注册公用设备工程师（暖通空调）考试给出了建议,对加强《传热学》的教学效果有一定的参考作用。     

人工神经网络在钢筋混凝土试验研究中的应用

本文用人工神经网络方法研究钢筋混凝土双向偏心受压构件的强度计算，采用ＢＰ算法，建立了一个四层网络，探讨了单元设置，学习率、指数衰减系数选取的具体方法。     

直立锁缝屋面系统风致破坏全过程研究

直立锁缝屋面系统广泛应用于厂房、车站、体育场馆等大型建筑中,但由于自重轻、柔性大,在强风作用下很容易发生局部损伤及整体破坏,探讨这类屋面系统的风致破坏模式和失效机理,以便提出有效的抗风措施很有必要.本文进行了足尺试验并结合精细有限元方法,对直立锁缝屋面系统在风荷载作用下的变形发展,直到局部屈曲,再到最终破坏的全过程进行...     

单层网壳结构在简单荷载下动力稳定分析

根据网壳结构的动力稳定判别准则，采用精确的空间梁单元切线刚度矩形式及大转角理论，通过二个典型算例，分别考查在突加阶跃荷载，简谐荷载及三角形脉冲荷载作用下，单层网壳结构的动力稳定性能，并得到了一些主要结论。     

导管架式采油平台的确定性波浪响应分析

文章介绍了用SACS软件进行导管架平台确定性波浪动力响应的分析方法和分析步骤,并对比波浪动力响应荷载和波浪静力荷载对平台产生的基底剪力,计算出波浪动力响应的放大系数．以期为百米水深左右导管架平台的设计提供简化计算的思路和概念上的认识。     

正交实验法薄壁压杆截面稳定性的优化

针对薄壁结构在工程中失稳破坏的问题,采用ANSYS软件对薄壁压杆双重非线性稳定进行分析,以薄壁压杆工字形截面尺寸为稳定极限载荷的影响因子,通过正交实验方法设计实验,得到了各个因子影响的显著性。翼缘宽度对稳定极限载荷的影响最大,翼缘厚度次之。最后依据多元线性回归原理建立了薄壁压杆稳定数学模型并对截面进行了优化设计,稳定极限载荷提高了30％。