埋地UPVC供水管线静力试验

目的分析埋地UPVC地下供水管线柔性接口的抗震性能,建立力与接1：7位移的数学模型．方法在覆土的条件下,对接口采用胶圈连接的6根管径为315mm和6根管径为200mmUPVC供水管,进行抗拉静载试验．结果6组覆土管径315mm和6组覆土管径200mm试件的P—S曲线的上下浮动不是很大,所以可以用平均值法取值．分别对两种管径的P—S关系曲线取平均值,进行二次曲线拟合和三次曲线拟合,建立了数学模型．结论二次多项式拟合误差较大,三次拟合误差较小,基本控制在±10％范围内,对于有精度要求实际工程中,建议使用三次多项式拟合模型．     

汽车乘员类型视觉检测算法

首先根据不同乘员类型体型轮廓的差异性,建立了基于低成本摄像头的乘员类型视觉检测系统;根据乘员图像样本数据信息量大而复杂的特点,利用Legendre矩阵对原始图像中乘员体型轮廓特征进行了描述;然后针对实验样本类型多、模式类型少的特点,引入智能模式识别中支持向量机的方法。通过样本数据的训练和参数的调整,建立了乘员类型识别器。最后进行了样本数据的测试。结果表明,用此种方法建立的识别算法能够以较高的准确率对乘员类型进行分类,为智能安全气囊系统提供准确的乘员类型信息。     

超大跨度斜拉桥纵向减震耗能塔、梁连接装置研究

在苏通大桥的塔、梁连接处分剐设置弹性连接装置和阻尼器.并选择恰当的弹性连接装置的弹性刚度以及阻尼器参数,利用Maxwell阻尼模型模拟黏滞阻尼器的滞回耗能特性,通过结构非线性地震分析的方法,对比了弹性连接装置与黏滞阻尼器的减震效果,分析表明弹性连接装置和阻尼器均能有效地减小梁端的地震位移,但阻尼器的效果更为理想.     

带约束拉杆L形方钢管混凝土组合柱轴压性能

为了研究带约束拉杆L形方钢管混凝土组合长柱的轴压性能,采用有限元软件ANSYS数值模拟和试验对比方法分析了带约束拉杆L形组合长柱的轴压性能,通过分析带约束拉杆L形组合长柱整体构件的屈曲模态、变形图以及各个部件的应力云图,验证了构件具有较高的受压承载力.结果表明,在钢管内部添加约束拉杆增强了钢管对混凝土的约束效应,提高了混凝土的轴心抗压强度与构件的整体承载力,为构件的工程应用提供了依据.     

汽车乘员约束系统及其新发展

随着我国汽车数量的大幅度提高,交通事故中汽车碰撞事故频发。汽车在碰撞及危险情况下,乘员约束系统能够显著降低车内乘员的伤害程度。本文综述了乘员约束系统的定义与组成,着重论述了目前国内外普遍使用的安全带、安全气囊、座椅等重要部件的结构、种类、保护作用、工作原理以及汽车乘员约束系统的新技术。     

Modification of -equation in the SSRC Guide for buckling of monosymmetric I-beams under transverse loads

Finite element buckling analyses of monosymmetric I-beams subjected to transverse loading applied at different heights with respect to the mid-height of the cross-section were conducted. Transverse loads consisting of a mid-span point load and a uniformly distributed load were considered in the investigation. Four types of end restraint also were considered. The method suggested in SSRC Guide was compared with the finite element method (FEM) results. In order for C-equation in the SSRC Guide to be applicable for monosymmetric I-beams, it must be modified to contain three variables; A_m, B_m, and D_m. The first two variables A_m and B_m are modified variables A and B in the SSRC Guide whereas the third variable, D_m, developed herein, is the new modification factor for monosymmetric I-beams. The applicability of this new design rule is limited to monosymmetric I-beams in which the degree of monosymmetry, ρ, is within the range from 0.1 to 0.9.     

Modelling of cold-formed steel sandwich purlin-sheeting systems to estimate the rotational restraint

Sandwich panels are attached to cold-formed steel purlins in roofs of industrial buildings to provide insulation. As the strength of the attached purlins is considerably increased due to the lateral and rotational restraints provided by the sandwich panels, estimating these restraints is important in the design of purlins. The rotational restraint is generally determined by experiments, as no design rules exist for sandwich purlin-sheeting systems. In this paper, a non-linear finite element model is presented to estimate the rotational restraint provided by the sandwich panels to the attached purlin. The model is validated with experimental tests and is in good agreement. In order to develop a design method for estimating the rotational restraint in sandwich purlin-sheeting systems, the model could be useful for parametric studies to investigate the influencing factors.     

Fire performance of axially restrained steel reinforcedconcrete columns

为了考察受轴向约束的型钢混凝土柱的耐火性能，以荷载比、偏心率和含钢率为参数，开展了7根轴向约束型钢混凝土柱的耐火试验。采用恒载升温模式，研究了火灾下受轴向约束的型钢混凝土柱的温度分布、位移、变形、耐火极限及破坏形态。试验结果表明：荷载比相同时，施加在轴心受压柱顶的竖向荷载大于偏心受压柱。对于轴心受压柱，高温下柱首先缓慢膨胀，然后逐渐压缩破坏；由于轴向约束分担了柱的竖向荷载，压缩变形随时间变化较为缓和，轴向约束延长了柱的耐火极限。对于偏心受压柱，高温下其膨胀变形大于轴心受压柱，且膨胀变形先增加再减小；轴向约束增加了柱的竖向荷载，缩短了柱的耐火极限。荷载比对轴向约束型钢混凝土柱耐火极限影响显著，荷载比越大，耐火极限越小。当荷载比不大于0.5时，偏心率越大，柱的耐火极限会相应增大。含钢率增加，会在一定程度上延长柱的耐火极限。     

楼顶钢塔一种独特的锚固方式及受力分析

以上海市公安局卢湾分局楼顶加设钢塔为研究对象,介绍了楼顶钢塔的设计方法.通过分析高层建筑上的钢塔在风荷载和地震作用下与下部结构的共同作用,说明在设计钢塔时必须考虑高层建筑对钢塔的影响,并提出一种新型的便于工程应用的钢塔与混凝土高层建筑的锚固方式,可供高层楼顶钢塔设计时参考.     

混凝土早期开裂试验方法评述

近年来,开裂问题日益成为混凝土材料研究领域的热点,主要针对国内外混凝土材料早期约束收缩开裂试验研究的进展进行了总结与评述。混凝土约束开裂试验方法的研究已经取得一定进展,但是混凝土开裂是多种因素综合的结果,因此正确评价混凝土的开裂性,还需要从多方面入手,仍需要大量的研究工作。