中波塔高强瓷绝缘柱脚性能研究

本文提出了一种新型柱脚设计方案，将非金属预应力筋安装在柱脚，运用施加预应力的方法改变柱脚应力性质，使其不仅易于抗压，也易于抗弯和抗拉，改善了高强绝缘陶瓷的脆性特性，提高其韧性。针对该新型柱脚设计方案，以一实际工程为算例，进行了AFRP张拉锚固方法探究试验以及瓷绝缘柱脚抗弯试验。通过试验，总结了AFRP筋施加预拉力的方法，并分析了该新型柱脚的受力性能。     

钢管结构法兰连接节点抗弯承载性能的试验研究

研究了钢管结构法兰连接节点的抗弯承载性能.通过试验方法，采用螺栓应变测量装置，对含4种基本形式的法兰连接节点的试件进行四点弯加载试验，考察了在节点受弯过程中螺栓和法兰板的受力特性.试验得到了其屈服荷载与极限荷载，并且与相应的有限元分析结果吻合良好.试验结果表明，法兰连接节点的受拉区存在明显的撬力作用，刚性法兰连接节点的撬力作用小于柔性法兰连接节点.法兰连接节点的安全储备约为1.2.     

Flexure-torsion Analysis of Variable-curvature-box Girder Considering Non-coincidence of Torsion Center and Gravity Center

In order to consider the effect of non-coincidence of torsion center and gravity center,the rectangular variable-curvature-box girder with vertical symmetrical axis is studied. Considering the influence of shear deflection and non-coincidence of torsion center and gravity center, the elastic equilibrium formulas are established. Based on deformation equations of the girder and the relations of inner forces and deformations,the flexure-torsion differential equations are developed. The equilibrium differential equations and Galerkin methods formulas for clothoid curved box girder are presented.     

Strength and Microstructure of Sulphoaluminate Cement Containing Ultra- Fine CaCO3

The existence of ettringite in sulphoaluminate cement hardened paste is mainly in the form of pole-like crystal,which causes unfavorable effect on the cement.In this paper the strength and microstructure of the sulphoaluminate cement containing ultra-fine CaCO_3 weze discussed.Experimet results show that the strength of sulphoaluminate cement was obviously improved by adding 3% of ultra-fine CaCO_3.After curing for 28d,the compressive strength of cement paste and mortar is 100.6MPa and 94.1MPa respectively,and the bending strength of the mortar reached 12.5MPa.SEM study on hardened paste of sulphoaluminate cement containing ultra-fine CaCO_3 showed that its structure was dense and homogeneous,there was hardly any massive crystall detected.     

A Comparative Study of Confined Concrete Models under Cyclic Loading

In this paper,four models are selected as the representatives and applied to nonlinear dynamic analysis program for space frames which is based on the beam-column elements using the finite element flexibility method and the fiber model.Park's test on combined axial and bending columns under cyclic loading are taken as the calibrations,comparisons to material and structural member level are drawn and the analytical results of various models are discussed.     

THE SIZE EFFECT OF THE FRACTURE ENERGY OF CONCRETE TESTED BY THREE POINT BENDING

This paper ainalyses the size effect of the fracture energy of concrete tested bythree point bending. It is shown that positive errors of test results of fracture energy increase,ornegative errors decrease with increasing of the specimen ize. The phenomenon is one of main causesresulting in the size effect of fracture energy.     

Carrying Capacity of Stretching-bending Rectifier

In accordance with the deficient elongation of the Stretching-bending Rectifier, as well as the severe wear and slipping of V-belt , the driving system velocity ratio of rectifier and the calculation formula of the theoretical elongation are deduced, which are based on the analysis of its structure and reeling principle. The carrying capacity of the driving system is also analyzed and it reaches the main reason for the elongation of the stretching-bending rectifier that cannot reach request, which is caused by the step less torsion of fixed output of the continuously variable transmission. The improvement measure which can be achieved by increasing the stiffness of the spring to increase the output torsion of the continuously variable transmission is proposed. Thus it makes the actual coefficient of elongation,which can satisfiy the producing request.     

制备工艺参数对菌丝体生物质材料性能的影响

为获得菌丝体生物质材料优化性能的最佳工艺参数,该研究以最小缓冲系数和弯曲强度为评定指标,通过3因素3水平正交试验研究了菌种接种量、基质颗粒度和水添加量对平菇菌丝体材料性能的影响。研究结果表明,正交试验9组菌丝体材料中菌丝平均直径最大为1 641 nm,最小为520 nm,前者后者的3.16倍,表明不同工艺参数显著（P<0.05）影响菌丝生长状态。影响菌丝体材料力学性能的最大因素是基质颗粒度,其次是水添加量和接种量。最佳工艺参数为接种量10%、基质颗粒度10 mm和水添加量60%,对应菌丝体材料的最小缓冲系数最低为4.17、弯曲强度最大为417.43 kPa,与发泡聚苯乙烯泡沫的弯曲强度相近。研究结果可为菌丝体材料制备工艺参数与性能的优化提供基础。     

不同穗型的3个粳稻品种的抗倒性研究

试验选用不同穗型的3个粳稻品种为材料,分析其抗倒机理及与倒伏密切相关的各性状,并初步探讨穗型与倒伏之间的关系。结果表明:株高与倒伏指数呈极显著正相关;节间长、茎粗、穗部性状等均与倒伏指数存在显著相关;直立、半直立穗型品种较弯曲穗型品种倒伏指数小,株高偏矮,基部茎杆节间短且粗壮坚韧,穗短而穂颈角小,表现出较好的抗倒性能。     

T型单边焊接接头弯曲疲劳裂纹位置研究

对Q345钢的T型单边焊接接头在弯曲循环载荷下的疲劳裂纹产生位置进行了研究,并计算了结构件的名义循环应力最大位置(不考虑焊接引起的截面变化),实际循环应力最大位置(考虑焊接引起的截面变化)。结果表明:疲劳试验中的名义应力最大位置不能反映焊接结构件的真实应力分布情况,而通过考虑焊接引起的截面变化的理论计算和有限元仿真得出的应力分布较为准确,由此得到的最大应力处为焊趾处,与裂纹位置一致。