短肢剪力墙在小高层住宅楼中的应用

小高层住宅采用短肢剪力墙结构，可以不露墙柱，减轻重量，减小地震效应等优点：通过具体工程实际分析计算，合理的布置竖向结构，提高其侧向刚度和抗扭刚度，并针对性的构造加强，在7度地震区，小高层住宅采用短肢剪力墙结构，其抗震性能尚可。     

薄壁构件约束扭转的近似计算

在开口薄壁板件的约束扭转中，外扭长的一部分由构件组成板件的抗弯刚度承担，另一部分由构件的抗扭刚度承担。     

铝合金超静定矩形薄壁梁的刚度理论研究与数值计算

对两端固支闭口薄壁梁的刚度进行理论研究,得出任意闭口截面梁在加载处的抗弯刚度及抗扭刚度计算公式,进而推导出矩形薄壁梁抗弯刚度及抗扭刚度的理论计算公式。通过算例对不同壁厚铝合金矩形薄壁梁的抗弯及抗扭刚度进行理论及数值计算,得出理论与数值的计算结果相同,从而验证了理论的正确性,为客车的矩形梁设计提供了一定的基础。     

中小转炉抗扭缓冲装置的设计与应用

弹簧式抗扭缓冲装置具有良好的柔性缓冲性能，安装、调试方便，代替１０ｔ转炉倾动机构的浮点铰链式抗扭缓冲装置，可减小转炉启动、制动时出现的动载荷、冲击载荷和扭振。     

某全铝车身客车结构强度与抗扭刚度分析

以某全铝车身客车为例,由原来的钢车身替换成铝车身来实现汽车的轻量化。并采用有限元法分析了铝车身在垂向工况、扭转工况、制动工况以及转向工况下的的结构强度和整车的抗扭刚度,为实现汽车的轻量化提供了可靠性的依据。     

高层建筑剪力墙中连梁的合理设计

〕针对高层建筑剪力墙中连梁的合理设计问题，以及设计中连梁截面尺寸的限值及配筋进行了分析探讨，给出了连梁截面高度及其刚度的调整公式，并提出了设计建议。     

基于等效耦合刚度的平面折展滑块机构分析

柔性铰链是实现平面折展柔顺机构运动的关键部分.如何设计得到柔度好、精度高的柔性铰链一直是柔顺机构研究的关键问题.综合考虑影响平面折展机构铰链刚度和精度特性的等效弯扭及拉压刚度,以LET铰链为例,分析在不同载荷下各个参数对弯扭与拉压等效耦合刚度的影响趋势,从而提出弯扭与拉压等效耦合刚度的概念.通过大量的实例计算和分析,推导出LET铰链弯扭与拉压等效耦合刚度的经验公式.基于等效耦合刚度经验公式,对平面折展柔顺滑块机构进行分析.应用等效耦合刚度公式与不应用等效耦合刚度公式两种情况的分析结果和有限元仿真结果表明,应用等效耦合刚度经验公式的滑块位移计算精度得到很大的提高,验证了等效耦合刚度经验公式的适用性.      

一种重卡车架轻量化结构设计及有限元分析

介绍一种基于有限元分析的钢铝混合重卡车架的结构设计：车架材料主要是500L大梁钢及6×××系铝合金挤压型材,由左右两支钢制纵梁、若干铝合金横梁组成主要受力框架。纵梁采用原主机厂设计结构样式,横梁断面设计成抗弯刚度和连接性较好的工字型,各零部件之间通过铆钉或高强螺栓连接。设计过程中通过有限元分析模拟了满载状态下的侧向工况和对扭工况,并重点分析了平衡悬架连接处的结构强度。经过反复分析、结构优化,车架各处应力均低于材料屈服强度,抗弯和抗扭刚度与原钢车架相当。对比结果表明,相比同类钢制车架,铝合金车架可减重40%。     

高层建筑的扭转破坏机理与抗扭措施

国内外历次震害表明,建筑物因扭转破坏占地震破坏的比例非常大,随着高层建筑结构平面,立面的多样化和复杂化,不规则结构的扭转破坏问题日益凸显。为了减轻地震时的扭转破坏,本文运用satwe软件,分别采用四种方案对周边构件进行刚度调整,得出加大离刚心最远处构件的刚度,最能有效地减轻扭转效应,并根据扭转机理提出了一系列的抗扭措施为工程设计提供依据。     

厦门金秋豪园高层住宅结构设计中几个复杂问题的处理

通过金秋豪园工程设计介绍，论述了高层结构设计中有关复杂地质情况、高位转换、平面不规则情况下设计考虑采取的措施，以及对转角区单片剪力墙设计的构造措施保证。     

Structural Characteristics and Applicability of Four-Span Suspension Bridge

A four-span suspension bridge which has two main 2,000 m spans is investigated with respect to the deformation characteristics. Generally, deformation behavior of the four-span suspension bridge is mainly influenced by rigidity of the center tower. This study is focused on properties such as bending and torsional rigidity of the girder, sag ratio, and dead load. The result of this investigation clarified that the lower rigidity under live load than the three-span bridge is caused by the smaller cable spring coefficient of the main span, which is 1/6 of the side span. Nevertheless, the tendency is stable and can be assisted by stiffened rigidity of the center tower. Live load deflection of the girder can be reduced to less than 1/200 of the main span length, which is useful and economical, by stiffening the bending coefficient of the center tower. Moreover, relatively lower rigidity of the center tower is sufficient for the 2,000 m span suspension bridge than for the 1,000 m span case, keeping the same deflection ratio. Three-dimensional sag geometry of the main cable is effective in limiting the torsional deformation, which is an especially important issue for the four-span suspension bridge caused by twist of the center tower.     

Performance Evaluation of FRP Bridge Deck Component under Torsion

Torsional response of fiber-reinforced polymeric (FRP) composites is more complex than conventional materials. Therefore, understanding torsional response of FRP components along with shear behavior leads to development of safe and accurate design specifications. Experimental data of multicellular FRP bridge deck components have been compared with simplified theoretical model studies focused on torsional rigidity, equivalent in-plane shear modulus, in-plane shear strain, and joint efficiency. Simplified classical lamination theory (SCLT) is used to predict torsional rigidity. Results from SCLT, experimental data, and finite-element analysis validate proposed methodology to find torsional rigidity. Data on torsional rigidity and equivalent in-plane shear modulus correlated (less than 12%) with results from SCLT and finite-element analysis. In-plane shear strain based on SCLT is also concordant with test results. In an FRP deck system with 100% joint efficiency, the two-dimensional effect (plate action) on torsional rigidity results in a 20% higher rigidity when compared to a beam model. However, if a refined model has only 80% joint efficiency, then plate action results in a 6% difference from the beam model. In addition, service load design criteria for FRP decks under shear must not excess 16% of the ultimate strain by accounting for environmental and aging effects.     

Flexural and Shear Rigidity of Composite Sheet Piles

The flexural and shear rigidity of pultruded composite sheet pile panels consisting of E-glass fiber-reinforced polyester are studied in this paper. The analysis consists of an experimental investigation and an analytical modeling to determine the resistance of the sheet pile panels to the deflections for design of composite sheet pile walls. Timoshenko’s beam theory was used to experimentally determine the flexural rigidity (EI) and shear rigidity (kAG) of the panel. Three- and four-point bending tests were performed on six different span lengths and the results were self-compared from the two independent tests. Analytical expressions for the flexural and shear rigidities were derived to allow the prediction based on the layered structure of pultruded shapes. The values computed from the analytical expressions were examined with the experimental results.     

Free Vibration of Three-Dimensional Orthotropic Uniform Shear Beam-Columns with Generalized End Conditions

The free vibration analysis of asymmetrical three-dimensional (3D) uniform shear beam-columns with generalized boundary conditions (semirigid flexural and torsional restraints, lateral bracings, and lumped masses at both ends) subjected to an eccentric end axial load in addition to a linearly distributed eccentric axial load along its span is presented in a classic manner. The five coupled governing equations of dynamic equilibrium (i.e., two shear equations, two bending moment equations, and the pure torsion moment equation) are sufficient to determine the natural frequencies and modal shapes. The proposed model which is an extension of a 2D model presented previously by the writer includes the simultaneous 3D coupling effects among the lateral deflections, deformations of the cross section along the member (shear, torsional and rotational), the translational, rotational and torsional inertias of all masses considered, an eccentric end axial load in addition to a linearly distributed axial load along its span, and the end restraints. Deformations caused by shear forces and pure torsion are considered. The effects of axial deformations, warping torsion and torsional stability are not included. The proposed model shows that the dynamic behavior of 3D shear beam-columns is highly sensitive to the coupling effects just mentioned, particularly in members with both ends free to rotate. Analytical results indicate that except for doubly symmetric members with concentric axial loads and with perfectly clamped ends, the natural frequencies and modal shapes of 3D shear beam-columns are determined from the eigenvalues of a full 8×8 matrix, rather than from the uncoupled equations of transverse (or shear-wave equations) and torsional moment equilibrium. Two comprehensive examples are presented that show the effectiveness of the proposed method.     

复合剪刃滚筒飞剪开发应用

作为板带材连续生产线上的关键设备,飞剪的剪刃侧隙调整精度直接影响了剪切质量,带材越薄对剪刃侧隙的精度要求越高,带材越厚对设备的冲击越大。本文将剪刃侧隙精度高的直剪刃和可减弱冲击的螺旋剪刃耦合在同一根刀轴上,并通过双侧齿轮传递扭矩提高抗扭刚度,拓宽了设备剪切厚度的范围,降低了设备加工制造成本。     

Dynamic deformation behavior of ultrafine-grained low-carbon steels fabricated by equal-channel angular pressing

The dynamic deformation behavior of ultrafine-grained low-carbon steels fabricated by equal-channel angular pressing (ECAP) was investigated in this study. Dynamic torsional tests, using a torsional Kolsky bar, were conducted on four steel specimens, two of which were annealed at 480 °C after ECAP, and then the test data were compared in terms of microstructures, tensile properties, and adiabatic shear-band formation. The equal-channel angular pressed specimen consisted of very fine, equiaxed grains of 0.2 to 0.3 μm in size, which were slightly coarsened after annealing. The dynamic torsional test results indicated that maximum shear stress decreased with increasing annealing time, whereas fracture shear strain increased. Some adiabatic shear bands were observed at the gage center of the dynamically deformed torsional specimen. Their width was smaller in the equal-channel angular pressed specimen than in the 1-hour-annealed specimen, but they were not found in the 24-hour-annealed specimen. Ultrafine, equiaxed grains of 0.05 to 0.2 μm in size were formed inside the adiabatic shear band, and their boundaries had characteristics of high-angle grain boundaries. These phenomena were explained by dynamic recrystallization due to a highly localized plastic strain and temperature rise during dynamic deformation.     

Static Cyclic Response of Masonry Walls Retrofitted with Fiber-Reinforced Polymers

The behavior of seven one-half scale masonry specimens before and after retrofitting using fiber-reinforced polymer (FRP) is investigated. Four walls were built using one-half scale hollow clay masonry units and weak mortar to simulate walls built in central Europe in the mid-20th century. Three walls were first tested as unreinforced masonry walls; then, the seismically damaged specimens were retrofitted using FRPs. The fourth wall was directly upgraded after construction using FRP. Each specimen was retrofitted on the entire surface of a single side. All the specimens were tested under constant gravity load and incrementally increasing in-plane loading cycles. The tested specimens had two effective moment/shear ratio, namely, 0.5 and 0.7. The key parameter was the amount of FRP axial rigidity, which is defined as the amount of FRP reinforcement ratio times its E modulus. The single-side retrofitting/upgrading significantly improved the lateral strength, stiffness, and energy dissipation of the test specimens. The increase in the lateral strength was proportional to the amount of FRP axial rigidity. However, using high amount of FRP axial rigidity led to very brittle failure. Finally, simple existing analytical models estimated the ultimate lateral strengths of the test specimens reasonably well.     

Elasticity Solution for Torsional Rigidity of Pretwisted Composite Strips

The tension-torsion problem for pretwisted antisymmetric laminated composite strips is formulated without ad hoc shell-type assumptions. No restrictions regarding the thickness-to-width aspect ratio are made. The elasticity equations are derived first and solved exactly for the torsional rigidity of orthotropic strips. An approximate solution is derived for angle-ply laminates. The torsional rigidity predictions are compared with a shell-type closed-form solution and finite-element simulations. An iterative method, which allows for the development of closed-form one-term approximations in a number of boundary-value problems, is presented. The accuracy of the method is illustrated by comparison with exact solutions for two benchmark problems.