钢筋

By using damping force between steel and columniation after pre-deformation, adjusting the type, quantity, length and position of the steel bar, and changing pre-deforrnation of the steel bars, all kinds of deceleration curves can be repeated.

介绍了自行设计的汽车模拟碰撞吸能器的特点及原理，利用LS—DYNA有限元分析软件对吸能器的波形复现原理进行了仿真分析，利用销柱间钢筋预变形产生阻尼力，改变钢筋的属性并调节钢筋的类型、数量、长度和位置，改变钢筋预变形量，复现出不同车重、不同碰撞车速所期望的减速度波形。

Longitudinal reinforcement has been modeled with discrete element and stirrup has been modeled with smeared element. Smeared element, stirrup has been modeled using membrane element in or on concrete isoperimetric element. The constitutive relationship and failure criterion for concrete is the inter-facial model.

在建立钢筋混凝土的有限元模型时，混凝土采用的单元为八节点六面体等参单元，钢筋单元分为两种情况，纵向钢筋采用分离式钢筋单元，箍筋采用埋藏式钢筋单元，即箍筋作为附着在混凝土等参数单元内或单元上的"膜单元"。

Usually translation of failure mode is ignored, which should result in much more serious conclusions. The main aim of this paper is to present the importance of nonsymmetry corrosion. Components under geometric center compression and large eccentric compression are taken as examples for bridge pier and column structure reliability analysis.

由钢筋锈蚀而造成的桥梁结构损伤已成为世界普遍关注的问题，在混凝土劣化机理、钢筋锈蚀机理、钢筋锈蚀量的预测以及锈蚀后钢筋性能变化等方面都进行了大量的研究并取得了卓越的成就，现役钢筋混凝土结构的可靠性鉴定及剩余寿命预测就是在这些成果的基础上进行的[1～5]。

It is common that reinforced concrete bridges are damaged with steel corrosion which not only reduces the strength of structures but also changes their failure mode if there exists nonsymmetry corrosion developed to some extent. Nonsymmetry corrosion can translate ductile fracture into brittle failure and translate flexural failure into torque failure, etc.

前言钢筋锈蚀是钢筋混凝土桥梁结构中最常见的一种损伤形式，钢筋锈蚀不仅削弱钢筋有效面积，而且能够引起钢筋体积膨胀，使混凝土保护层开裂，为腐蚀介质提供更加便易的入侵渠道，从而加速结构损伤，导致结构提前破坏。

Base on the problem of large quantity fatigue loads on corroded R.C. structure and small quantity study of its mechanical property, bending resistance fatigue test of corroded R.C. beams is discussed in this paper. The influence of stress ratio and re-bar weight loss ratio on bending resistance fatigue performance of corroded R.C. beams are researched, and the relation between strains of corroded re-bars and fatigue life of beams are obtained. The main research contents and conclusions are as following: 1. Under the fatigue loads, the overstrain of concrete approximately coincidences three stages strain development and accumulation rule, and the mechanical property of concrete is deteriorated. The fatigue damage of concrete is accumulated. The overstrain of re-bars increases and the increase rate decreases.

鉴于实际工程中大量存在腐蚀钢筋混凝土结构承受反复荷载作用，但其力学性能研究不多的问题，本论文进行了锈蚀钢筋混凝土梁抗弯疲劳试验，研究了应力比和钢筋锈蚀率对锈蚀钢筋混凝土梁抗弯疲劳性能的影响，得出了锈蚀钢筋的应变与构件疲劳寿命之间的关系曲线，主要研究内容及结论如下：(1)在循环荷载下，混凝土残余变形基本符合三阶段变形规律，力学性能劣化，疲劳损伤积累。

Combining with the National Natural Science Foundation ofChina(No.50478032), following researches were done in this thesis: 1 The variation regularity of the ultimate anti-bending capacity of therectangular-sectioned beam with different corrosion has been obtained through thequalitative analysis of 48 beams (32 corroded beams and 12 comparing beams) withaccelerated corrosion; 2 The conclusion has been obtained that the strain of corroded steel bar andconcrete no longer fit in with the assumption of plane section through the analysis ofthe strain data, the strain relation of steel bar and concrete in the mid-span section ofvariously corroded beams at ultimate has been obtained. Through the building of newgeometric relation, the expression of the height of compressive area in the corrodedbeam with rectangular section has been deduced, and the formula with corrosion rateas the main variable for the anti-bending capacity of the corroded concrete beam hasbeen suggested and verified by experiment.; 3 The influence of steel bar corrosion and the concrete regression to the flexureductility coefficient of the corroded structure component has been analyzed. Based onthe relation of steel bar and concrete at yield and ultimate, the expression for theflexure at yield and ultimate of corroded reinforced concrete beam, and the model forthe calculation of the flexure ductility has been built.

本文结合国家自然科学基金项目(50478032)"既有钢筋混凝土桥梁时变可靠度研究"，主要进行了以下研究工作： 1通过对48根快速锈蚀钢筋混凝土矩形截面梁(32根锈蚀梁和12根对比试验梁)数据的定性分析，得到了不同锈蚀率下，锈蚀钢筋混凝土矩形截面梁极限抗弯承载力的变化规律； 2通过对应变数据的分析，论证了锈蚀构件钢筋和混凝土的应变不再符合平截面假定的结论，并通过回归分析得出了不同锈蚀率的螺纹钢筋梁和光圆钢筋梁在极限弯矩作用下，跨中截面处钢筋应变和钢筋处混凝土应变的关系，通过构造新的几何关系，得出了锈蚀钢筋混凝土矩形截面梁计算受压区高度的表达式，既而得出了以锈蚀率为主要变量的锈蚀钢筋混凝土矩形截面梁的正截面抗弯计算建议公式，并通过试验数据加以验证； 3分析了钢筋锈蚀和混凝土劣化对锈蚀构件曲率延性系数的影响，结合钢筋屈服和极限弯矩两种状态下钢筋和混凝土的应变关系，分别得到了锈蚀钢筋混凝土矩形截面梁屈服曲率和极限曲率的计算表达式；既而推导出曲率延性系数的计算模型。

Its amount has relation with acting load. The influence on sectional curvature of bending components is the greatest one, the ultimate curvature of corroding section decrease obviously, and the sectional curvature increases rather sharply with the increase of rust rate during the process of corrosion. The anti-cracking capacity of prestressed bending R. C. components may be damage. For the convenience of engineering usage and damage evaluation of structure, this paper presents a concept of sectional damage coefficient on the foundation of experimental and treatment study.

试验与理论研究均表明，受压区钢筋锈蚀后对普通钢筋混凝土和预应力钢筋混凝土受弯构件的承载力影响均不大，但对构件的正常使用性能有较显著的影响，受压区钢筋锈蚀过程中，截面刚度有较显著的下降，挠度及受压区混凝土压应变随锈蚀量增加而增加，增加值与使用荷载大小有关；受弯构件的截面曲率所受影响最大，锈蚀后截面的极限曲率有明显的下降，在使用荷载作用下，截面曲率则随钢筋锈蚀量的增加而有较显著的增加；而预应力混凝土受弯构件的抗裂度会下降。

HRB400 steel bars, the 400 MPa hot rolled steel bar, which is called new grade III steel bar, has been taken as the one of 10 new technical spreading the application mainly, listed in revised newly code, so spread application as leading steel bar in reinforced concrete structure.

HRB400级钢筋已作为高效钢筋被列为重点推广应用的建筑业10项新技术之一，早在1998年建设部就明确提出：&新Ⅲ级钢筋是专门为建筑结构应用开发的新型钢筋，该钢种已列入新修订的国家规范标准，应大力推广使之成为我国钢筋混凝土结构的主导钢筋&(建设部建[1998]200号文)。

Leading products: GQ40-type reinforcing steel cutting machine, GQ50-type reinforcing steel cutting machine, GQ16-type reinforcing steel cutting machine, GW40-type steel bending machine, GW40C steel semi-automatic bending machine, GW40-1 type steel bending machine, GW50 steel bending machine type, GF - l6-type steel stirrup bending machine, GF-l8-type steel stirrup bending machine, GT6-12-type steel Straightening Machine, HMD, HMR vane surface wipe-ray machine, JQ70-type rammers, JQ85-B-type ( Honda GX120) rammers, HQL18 (12)-type road-cut machine

主导产品：GQ40型钢筋切断机、GQ50型钢筋切断机、GQ16型钢筋切断机、GW40型钢筋弯曲机、GW40C型半自动钢筋弯曲机、GW40-1型钢筋弯曲机、GW50型钢筋弯曲机、GF-l6型钢筋箍筋弯曲机、GF-l8型钢筋箍筋弯曲机、GT6-12型钢筋调直机、HMD、HMR叶片式地面抹光机、JQ70型冲击夯、JQ85-B型(本田GX120)冲击夯、HQL18(12)型路面切缝机

Frame working reinforcement main useⅠLevel steel bar, stirrup main use TheⅡlevel steel bar, the staircase uses the reinforced concrete beat staircase; As a result of the column net limit, the foundation uses under the reinforced concrete column the independent foundation.

框架受力钢筋主要采用Ⅱ级钢筋，箍筋主要采用Ⅰ级钢筋，楼梯采用钢筋混凝土板式楼梯；由于柱网的限制，基础采用钢筋混凝土柱下独立基础。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。