Fatigue crack/residual stress field interactions and their implications for damage-tolerant design

Residual stress fields are now widely accepted to have significant influence on fatigue crack growth. Tensile stresses have detrimental effects on fatigue lives, whereas compressive residual stresses can be beneficial. Control of fatigue lives via residual stress is now established in many industrial applications, using techniques such as shot peening or cold expansion. However, knowledge of the processes that occur when a fatigue crack grows through a pre-existing stress field is far from complete. Although the residual stress field will clearly have an effect on crack growth, the crack will equally have an effect on the residual stress field. The determination of this effect is not trivial, and direct measurement may be the designer’s best safeguard. This article outlines the complementary effects that a growing fatigue crack and a residual stress field have on each other. Two types of residual stress field are considered: mechanically induced and thermally induced. The results are discussed in terms of the implications that residual stress interactions have for damage-tolerant-based design.     

重庆市快速路规划建设标准探讨

目前世界上许多城市都己建成一定规模的城市快速路系统,而我国十多年来虽然建设了一定数量的快速路,但各城市的快速路建设标准和服务水平不尽统一。重庆是典型的山地城市,其地形地貌等自然条件明显有别于平原城市,其快速路的规划建设目前还处于起步阶段,急需一套适应本地特色的建设标准予以指导。本文从快速路历史背景和规范定义入手,并结合《重庆市快速路系统建设规划》实践,抛砖引玉地提出重庆山地城市快速路建设相关标准和在规划实施中弹性处理原则,以供参考。     

建筑工程设计常用结构分析软件应用探讨

简述了选用合适的软件进行结构计算分析的必要性,选取常用的结构分析软件ETABS,SAP2000,MIDAS/GEN,EPDA,ABAQUS,简要概述了其基本功能,对比了软件弹塑性分析的计算模型,并对软件的分析功能进行了总结,提出了选用软件的一些建议。     

高校新校区景观设计的探析

介绍了太原师范学院新校区景观设计的构思和理念,对于不同尺度和不同使用功能校园空间的景观设计手法作了论述,强调了景观设计要合理利用现有自然环境,考虑学校的文脉,注重学校的文化氛围的塑造,使景观设计服务于校区的规划设计。     

井点抽水时饱和分层地基的传递矩阵解

从直角坐标系下三维Biot固结问题控制方程出发,引入位移函数,并对各个变量进行关于时间t的Laplace变换和关于x、y的双重Fourier变换,得到了z=z处和z=0处的8×8传递矩阵;根据各土层间以及井点抽水作用处的连续条件、边界条件,并结合传递矩阵的性质和Laplace-Fourier逆变换技术,求得井点抽水时饱和分层地基的真实解答。数值计算结果表明,随着井点抽水时间的增加,饱和多层地基的地表位移逐渐增大。     

健康居室环境的营造

阐述了健康与人居环境的关系，从心理健康和身心健康要求的角度，提出营造健康人居环境的观点，并对老年居住环境设施建设提出了几点原则，即尊重自然，尊重人，实现设计与建造设计的美的原则，提出应从住区空间的尺度重新考虑居住空间形态的问题。     

Soil sealing footprint as an indicator of dispersed urban growth: a multivariate statistics approach

The present study introduces a set of indicators derived from high-resolution land-use maps with the aim to illustrate the spatial distribution, intensity, and diversity of sealed soils in a Mediterranean region (Rome, Italy) shifting from a mono-centric spatial organization toward a dispersed urban agglomeration. A multivariate approach provides a comprehensive assessment of Rome ‘sealing footprint’, classifying local districts according to different imperviousness profiles. Results illustrate the rearrangement of the land-use structure determined by suburbanization with higher soil consumption and lower land-use efficiency. The approach is considered a promising tool to inform policies for a spatially balanced and land-saving urban development.     

中国南北人群在中性环境下的生理适应性和主观评价

研究中国南北人群在中性环境下,生理适应的自主神经调节和主观评价差异。采用实验设计,遴选16名南方大学生和16名北方大学生,测试生理参数,包括皮肤温度、心率、心率变异性(HRV)、血容量(BVP)、肌电(EMG),填写主观问卷。实验结果发现:1)中性环境,北方人群感觉是舒适的,各项评价指标接近中性和适中,数据较集中;南方人群感觉稍热,评价数据较离散,但热舒适(TCV)(p=0.1060.05)、可接受程度(p=0.8380.05)等几个主观评价与北方人群相比没有显著差异,说明南方人群有较宽的热中性温度区和较好的环境忍耐力;2)南北人群在中性环境下,平均皮肤温度有显著差异(p=0.0060.05),且身体躯干部位的皮肤温度显著高于四肢皮肤温度(p=0.0090.05;p=0.0430.05;p=00.05;p=00.05;p=0.0020.05),四肢皮肤温度差异不显著,肌电无显著差异(p=0.9610.05)。心率和心率变异性的LF/HF比值,均值有差异,但不显著((p=0.2650.05;p=0.6180.05),但BVP有显著差异(p=00.05)。     

空调房间的温度控制与节能

介绍了空调房间室内温度控制的途径和方法，分析了空调房间内空气计算参数温度对热舒适性和建筑能耗的影响，指出在一定温度和湿度的范围内，通过提高室内温度的途径来减少空调系统能耗的方法。     

议沉降后浇带的施工技术

介绍了混凝土工程中沉降后浇带的定义及设置方法,并重点讨论了后浇带混凝土的浇筑及质量控制措施,总结了后浇带施工的注意事项,从而有效防止建筑物的不均匀沉降。