基于开放性BIM技术的传统建筑数据库建设中的信息交换研究

随着计算机技术的高速发展和各地传统建筑的破坏,计算机技术的应用在对传统建筑进行数字化保护以及方便现代建筑师设计方面展示了其优越性和必要性。然而目前大多数相关研究都是依赖于某种软件进行,这样就存在很大的局限性。本文对韩国正在进行的基于开放性BIM技术的传统建筑数据库的建设进行了介绍。作者着重介绍了该项目中利用IFC属性集进行信息交换的部分,由于我国的传统建筑和韩国传统建筑存在很多的相似性,希望能对我国的相关研究提供一些建议和方法。     

3种被动式微混合器的性能对比及压损分析

通过数值模拟的方法对3种不同结构的被动式微混合器进行了研究,同时对3种被动式微混合器的混合性能进行了对比,并进一步研究了微混合器的压力损失。结果显示,内肋形微混合器在5种速度条件下的混合性能要优于其他两种微混合器,而且随着流量越来越大,其压力损失也越来越大;内肋形微混合器的压力损失最大,Z形微混合器的次之,Y形微混合器的最小。     

Preparation and properties of exfoliated nanocomposites through intercalated a photoinitiator into LDH interlayer used for UV curing coatings

The exfoliated polymer/layered double hydroxide (LDH) nanocomposites based on MgAl were prepared through intercalating a photoinitiator into LDH interlayer, following by UV irradiation induced polymerization. The fragmental photoinitiator, 2-hydroxy-2-methyl-1-phenylpropane-1-one (1173) firstly reacted with isophorone diisocyanate (IPDI) to obtain the semiadduct, 1173-IPDI, and then reacted with the LDH modified by aminoundecanoic acid, obtaining LDH-1173 with an intercalated microstructure, which was characterized by FTIR, XRD, and TGA measurements. The obtained LDH-1173 was mixed with the multifunctional acrylate oligomer and monomer, and then exposed to a UV lamp to prepare a polymer/LDH nanocomposite. From the XRD, TEM and HR-TEM analysis, as well the photopolymerization kinetics investigation, it was found that the LDH-1173 effectively initiated the photopolymerization of acrylates, and formed exfoliated polymer/LDH nanocomposites. However, the mostly intercalated polymer/LDH nanocomposites were obtained for the systems with additional 1173 except for LDH-1173 addition. Compared with the pure polymer material, both the exfoliated and intercalated polymer/LDH nanocomposites exhibited the enhancements in mechanical and thermal properties, as well as hardness.     

一种化工换热设备用保温涂料的研究

针对一种用于化工换热设备的保温涂料,通过正交试验进行了组分优化,得到了最佳涂料配方,并分析了涂料主要组分对保温性能和黏结强度的影响。     

乳液型纸塑复合胶粘剂的研究进展

纸塑复合已成为印刷后精加工的重要方法,纸塑复合用胶黏剂是复合质量的关键因素.乳液型纸塑复合胶黏剂是现代包装、印刷行业应用较为广泛的一种新型胶黏剂,其种类较多.着重介绍了聚丙烯酸酯类、醋酸乙烯-乙烯共聚乳液及其他多元共聚乳液类的纸塑复膜胶现状及其研究进展.并指出了目前存在的问题及发展方向,提出今后的研究方向是开发环境友好、高同含量和功能性纸塑复合胶黏剂.     

工程常用混凝土材料的性能与应用

本文从工程应用角度对混凝土材料的性能与应用作了简要的论述。     

Experimental analysis of cross-laminated timber panels in fire

Design models of timber structures in fire usually take into account the loss in cross-section due to charring of wood. For cross-laminated timber panels in fire only little information on charring is available. The paper describes and discusses the results of an extensive testing programme on the fire behaviour of cross-laminated timber panels under ISO-fire exposure. The fire tests were performed on the small horizontal furnace (1.0×0.8 m) at the Empa in Duebendorf. Particular attention is given to the comparison of the fire behaviour of cross-laminated timber panels with homogeneous timber panels. The results of the fire tests showed that the fire behaviour of cross-laminated timber panels is strongly influenced by the behaviour of the adhesive used for bonding the cross-laminated timber panels. Depending on the properties of the adhesives at elevated temperatures falling off of the charred layers was clearly observed during the fire tests, leading to increased charring rates in comparison to homogeneous timber panels. This is the same effect as observed for initially protected timber members after the fire protection has fallen off. For the specimens where no falling off of the charred layers was observed the fire behaviour was similar to that of homogeneous timber panels.     

以新制度经济学及产权理论解读城市规划

长期以来,我国城市规划的理论研究偏重物质形态和技术方案,经济学研究相对较少。大量的城市规划试图采用理论上或图纸上的最优空间方案解决复杂的现实问题,往往造成方案无法实施,或是实施后效果不好的问题。面对市场经济环境,重构城市规划理论的经济学基础十分必要而迫切。从产权概念出发,介绍了以新制度经济学及产权方法为理论基础的新视角,来重新解读一些城市规划问题。但对于新制度经济学的一些基本观点,应采取批判的态度,将其作为研究方法加以应用,而不是全盘接收。     

Dynamic analysis of walls strengthened with composite materials

The bidirectional dynamic behavior of walls strengthened with composite materials is studied. For that purpose, a multi-layered high order finite element is developed. The finite element accounts for the bidirectional (plate-type) dynamic behavior and for the interfacial interaction between the adhesively bonded components. The formulation uses a viscoelastic first order shear deformation orthotropic plate theory for the independent modeling of the existing wall and the composite layers and a high order theory for the displacement fields of the adhesive layers. The Finite element framework simplifies the coupling with adjacent structural elements and the use of standard computational procedures. The convergence of the formulation and two numerical examples are studied. The first case studies the response of a strengthened wall to a step base acceleration. The second case studies a wall built in a surrounding frame and strengthened on the outer face. The numerical study examines the capabilities of the model and reveals some of the unique aspect of the dynamic response, including the effects of the orthotropy and orientation of the strengthening system. It also highlights the potential of the high order finite element to become a platform for the modeling and dynamic analysis of the strengthened wall.     

Bio-inspired design of aerospace composite joints for improved damage tolerance

This paper uses a bio-inspired design strategy based on tree branch joints to improve the damage tolerance of co-cured composite T-joints. The design of tree branch joints at different length scales from the microstructural to the macro-length scale was investigated. X-ray computed tomography of a pine tree revealed three main features of tree branch joints which provide high structural efficiency and damage tolerance: integrated design with the branch embedded into the centre of the trunk; three-dimensional fibril lay-up in the principal stress directions; and variable fibril density to achieve iso-strain conditions through the joint connection. Research presented in this paper adapts the embedded structural feature of tree joints into a carbon/epoxy T-joint. The flange plies were embedded to 25%, 50% and 75% of the depth of the skin of the composite T-joint to mimic the design of tree branch joints. Experimental testing revealed that the bio-inspired T-joint design with integrated adherends had increased normalised inelastic strain energy (defined as ductility), increased normalised absorbed strain energy to failure, and higher load-carrying capacity following damage initiation (damage tolerance) compared to a conventionally bonded T-joint. However, these improvements were achieved at the expense of earlier onset of damage initiation in the T-joints.