有限元在计算简支梁屈曲荷载中的应用

介绍了有限元ANSYS中壳元模型的建立步骤,并利用有限元ANSYS程序对简支梁屈曲荷载进行了求解,通过理论分析与有限元结果的比较,验证了有限元ANSYS程序计算结果的正确性,并为外形和受力复杂的简支杆件的稳定承载能力的计算提供了参考依据。     

预应力简支钢箱梁的数值仿真分析

根据预应力简支钢箱梁的受力特性,考虑预应力索与钢箱梁的相互作用,建立了有限元计算模型,有限元计算值与实测值吻合较好。基于有限元分析软件ANSYS,对所建模型进行了全过程仿真计算,并对梁的荷载—位移曲线,跨中截面应力以及跨中截面应变进行了较为详细的分析。     

先简支后结构连续T梁受力特性分析

以3-40 m预应力混凝土先简支后结构连续T梁为例,简要介绍了西部开发省际公路通道重庆绕城公路中广泛采用的先简支后连续梁桥的结构设计特点和计算方法,指出了该计算方法同样适用于简支转连续空心板或小箱梁桥,以推广该计算方法的应用.     

Synthesis and Functionalization of Oriented Metal–Organic‐Framework Nanosheets: Toward a Series of 2D Catalysts

Synthesis of metal–organic frameworks (MOFs) is based on coordination‐driven self‐assembly of metal ions and organic ligands. However, to date, it remains difficult to adjust the coordination behaviors of MOFs and then control geometric shapes of nanostructures; especially their morphologies in 1D nanofibers or 2D nanosheets have seldom been explored. Here, a facile route at room temperature and ambient pressure is reported for the preparation of copper‐based MOFs with low‐dimensional shapes (i.e., nanofibers, nanorods, nanosheets, and nanocuboids), via thermodynamic and kinetic controls over the anisotropic growth. Importantly, the as‐prepared 2D MOF nanosheets with monocrystalline nature (100% exposed {010} facets) provide a material platform to the fabrication of 2D supported metal nanocatalysts. First, the MOF nanosheets can serve as a self‐templating solid precursor to prepare different CuO and CuO‐Cu₂O nanocomposites, or even Cu metals via thermolysis or reduction under controlled atmospheres. Upon their formation, second, ultrafine noble metal nanoparticles (e.g., Au, Ag, Pt, Pd, Au_0.4Pt_0.6, Au_0.4Pd_0.6, and Au_0.3Pt_0.3Pd_0.4) can be exclusively anchored on the external surfaces of the MOF nanosheets. To show their open accessibility, catalytic activities of the derived catalysts have been evaluated using CO₂ hydrogenation and 4‐nitrophenol reduction in gas phase and liquid phase, respectively.     

某住宅楼扣件式钢管脚手架设计

本文主要介绍一幢混合结构住宅楼外墙装修脚手架的设计计算过程。对扣件式钢管脚手架的纵向水平杆和横向水平杆的强度及变形、立杆的稳定性、扣件抗滑力、最大搭设高度、连墙件及地基承载力等方面进行了计算和验算。     

我国预应力混凝土公路桥的发展与现状

本文叙述我国预应力混凝土桥的发展历程和现在情况.近几年来,我国建造了多座预应力混凝土桥,结构型式有简支梁、T型刚构、连连梁、连续刚构、斜拉桥与组合式拱桥等.在每种桥型中,选择具有代表性的桥梁,对其结构特点,设计与施工新技术,加以分析讨论.使能互相交流知识,总结经验,以资提高技术水平,促进我国桥梁建设的新发展.     

负载型离子液体吸附分离CO2的研究现状及展望

人口增长与全球工业化的加速发展促使化石能源需求量逐年递增,由此导致大气中二氧化碳（CO₂）含量快速上升并引发了全球系列气候问题,“碳达峰·碳中和”背景下的CO₂减排刻不容缓。传统工业捕集CO₂方法由于能耗高、选择性较差、溶剂损耗大等问题限制了其大规模推广应用,离子液体因其极低挥发性、强的气体亲和性、可调的结构性质等特点在CO₂捕集分离领域逐渐显示出独特优势,但离子液体特别是功能化后通常黏度较高或室温呈固态,导致气液传质效果差或无法直接应用于吸收分离过程。负载型离子液体兼具离子液体和多孔材料的共同优势,不仅能提升选择性分离效果,有效避免离子液体直接吸收造成的高黏度,还可拓展离子液体应用范围,具有广阔的发展前景。重点总结了近些年物理和化学负载型离子液体在CO₂吸附分离方面的研究现状和进展,并对负载型离子液体捕集分离CO₂研究的发展趋势进行了展望。     

钢筋混凝土简支单向板最小板厚的确定

通过对简支单向板推荐板厚的挠度与裂缝宽度的计算,提出了满足挠度与裂缝宽度要求的建议板厚。     

End bearing capacity of a single incompletely end-supported pile based on the rigid plastic finite element method with non-linear strength property against confining stress

An Incompletely End Supported Pile (IESP) is a pile in a soft soil layer underlain by a hard soil layer that does not reach the bottom hard layer in practice. This study estimates the end bearing capacity of IESP by using an inhouse Rigid Plastic FEM code (RPFEM), considering shear strength non-linearity of soil against confining pressure, and soil-foundation interaction. The effect of the distance between the pile tip and the bottom hard soil layer (d/B) on the end-bearing capacity of IESP was mainly investigated for three types of soil: cohesive soils, cohesionless soils and intermediate soils. Also, theratio (r) of the end bearing capacity of the pile when it reaches the bottom hard layer to that of the pile when the bottom layer has no influence was was considered. By considering the shear strength non-linearity, the end bearing capacity was accurately estimated. The estimations were consistent with previous analytical, experimental and numerical solutions. It is found that the end bearing capacity inversely decreases with the distance d/B and becomes constant around d/B = 3. Based on the results, a formula for estimating the end bearing capacity of IESP is proposed. Comparisons with methods in existing literature confirmed the reliability of the proposed equation.     

中空纤维膜萃取与超滤耦合富集铟In(Ⅲ)

研究中空纤维膜萃取与超滤耦合工艺从模拟含铟酸性浸出液中提取铟的效率,考察反萃相与萃取相混合配比、混合液流速、原料液与混合液温度变化等参数对系统提铟效果的影响。结果表明:反萃相与萃取相体积之比(A/O)在一定范围内,在A/O=4时系统反萃相中In(Ⅲ)的富集量达到最大;随混合液流速的增大,系统的传质性能降低;原料液与混合液等温变化对系统提铟效果的影响并不显著。对比含In(Ⅲ)、Fe(Ⅲ)、Zn(Ⅱ)三组分原料液与In(Ⅲ)、Fe(Ⅲ)两组分原料液的实验结果可知,原料液中Zn(Ⅱ)的大量存在会干扰In(Ⅲ)的萃取,需要对多组分原料液进行预处理以排除竞争离子的干扰,才能实现较好的提铟效果。