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1.
采用试验方法对钢绞线加固混凝土梁进行了研究,结果表明,加固后混凝土梁的抗弯承载力和刚度得到了提高,这种加固施工方法可行。  相似文献   

2.
采用试验方法对钢绞线加固混凝土梁进行了研究,结果表明,加固后混凝土梁的抗弯承载力和刚度得到了提高,这种加固施工方法可行。  相似文献   

3.
对9根玻璃纤维布加固的钢筋混凝土梁和3根对比梁进行了抗弯性能试验研究. 试验中考虑了配筋率、加固量、剪跨比与混凝土强度等级4个参数. 试验结果表明, 经玻璃纤维布加固的钢筋混凝土梁抗弯承载力有显著提高; 混凝土强度、配筋率、加固量对极限荷载有显著影响; 剪跨比对加固梁的破坏形态有影响. 根据不同的破坏模式, 提出了抗弯承载力计算方法.  相似文献   

4.
通过分析高强预应力混凝土板桩截面的抗弯系数的3种不同计算方法,探讨了板桩截面形状、尺寸与抗弯系数之间的关系。与现有的其它类似板桩产品相比,新研发的高强预应力槽形板桩有效提升了截面抗弯系数,提高了混凝土板桩的抗弯弯矩和抗裂弯矩。研究成果将对高性能预应力混凝土板桩优化设计和施工具有指导意义。  相似文献   

5.
为了探究复合材料帽型加筋板在受到冲击损伤后抗弯刚度折减和强度降低的情况,以及对筋条R区填充捻子条的影响,在无损伤情况和预制特定冲击损伤情况下对两种构型的帽型加筋板进行四点弯曲试验。借助超声无损探伤设备检测损伤情况,并分析试验件载荷-位移曲线和应变等信息。结果表明:冲击损伤影响了复合材料帽型加筋板在承受弯曲时的刚度强度以及损伤扩展过程,在帽型加强筋R区填充捻子条可以提高加筋板的抗弯刚度和初始破坏载荷,但弯曲性能受冲击损伤影响更大。本研究可为飞行器、船舶、汽车的复合材料结构设计提供参考依据。  相似文献   

6.
钢纤维混凝土中掺入的钢纤维与混凝土之间的黏结力,增加了混凝土的抗拉强度。同时钢纤维弹性模量高于基体混凝土的弹性模量,起到增强混凝土结构的阻裂和增韧,使以主拉应力控制的抗剪强度、抗弯强度、抗扭强度明显改善,提高混凝土构件的整体刚度。剖析钢纤维混凝土受弯构件的荷载效应标准组合作用下刚度计算方法,认为现行设计规范规定的钢纤维混凝土梁的刚度计算表达略显保守。  相似文献   

7.
通过对锈蚀钢筋混凝土构件的低周反复荷载试验,讨论了钢筋锈蚀对混凝土构件的滞回曲线、骨架曲线、刚度、延性、耗能能力、承栽力等不利影响,提出了锈蚀钢筋混凝土构件抗剪承栽力与抗弯承载力计算表达式。  相似文献   

8.
首先对我国现行SRC-RC竖向混合结构过渡层的设计要求和相关规定提出了不同的看法,建议采用SRC-RC转换柱进行型钢混凝土柱到钢筋混凝土柱的过渡。介绍了SRC-RC转换柱的优点,并在RC柱和SRC柱截面抗弯刚度基础上根据抗弯刚度等效原则合成SRC-RC转换柱的截面抗弯刚度。最后给出了SRC-RC转换柱侧移刚度计算公式。  相似文献   

9.
为了研究高阶模态对底部带BRB的铰支墙(HWBB)框架结构的影响,建立了HWBB-铰接框架和HWBB-抗弯框架的分布参数模型.将铰支墙简化为弯曲梁、BRB简化为转角弹簧、抗弯框架简化为剪切梁.推导出2种分布参数模型的振动方程,求出各阶周期、各个振型及内力和位移的数值解.研究了相对刚度比以及转动刚度比对高阶模态效应的影响.对于弹性结构,整体位移及抗弯框架中的剪力由一阶模态控制,而墙中的剪力和弯矩受高阶模态影响较大.同时研究了BRB屈服对HWBB-铰接框架结构内力分布的影响.结果表明:在BRB屈服后,原一阶模态将不再对内力产生贡献,而高阶模态对内力贡献作用将增加.但BRB屈服后位移对高阶模态不敏感、仍由一阶模态控制.参数分析表明:在墙的抗弯刚度达到一定值前,随着墙抗弯刚度的增加,结构的位移会逐渐减小;随着转动刚度的增加,前三阶周期会减小;随着转动刚度比的增加,一阶模态的基底剪力贡献系数减小,但二阶和三阶模态的基底剪力贡献系数增加.  相似文献   

10.
预应力混凝土箱梁桥因截面抗弯、抗扭刚度大,施工方便,造价低廉等优势而颇具竞争力,该桥型近些年无论在规模还是跨径方面都取得了较大突破,但随之而产生的问题也越来越多,其中开裂问题在已建或在建工程中均较为普遍。因此,研究预应力混凝土箱梁桥裂缝成因及控制策略,对推进具有重要的意义。  相似文献   

11.
应用有限差分法,计算出碰摩转子的挠曲振型和截面弯矩分布的变化情况,从而直观地揭示了碰摩过程中转子截面应力的增长规律,对一些旋转机械重大事故中转轴出现多个断口的成因做了初步解释.  相似文献   

12.
电阻应变计法测量组合变形轴的扭矩和弯矩   总被引:1,自引:0,他引:1  
分析用电阻应变计法测定组合变形轴的扭矩和弯矩时,如何布置应变片和组成测量电桥。所述思路,步骤和方法,可适用于其它组合变形构件。  相似文献   

13.
为了提高水泥胶砂的力学性能,提出在水泥胶砂中掺加外加剂的方法,通过在水泥胶砂中单掺引气剂、复掺引气剂与减水剂两种途径,进行水泥胶砂抗折强度检测试验,对比确定水泥胶砂力学性能最优的引气剂型号及其最佳掺量.结果表明:引气剂与减水剂复掺时水泥胶砂的抗折强度明显大于引气剂单掺时水泥胶砂的抗折强度,2#引气剂最能满足水泥胶砂抗折强度要求.  相似文献   

14.
This paper presents a method to determine driving resistance with rebound of pile-top during pile driving. The soil around the pile shaft is assumed to be rigid-plastic, while that under the pile-tip is assumed to be ideally elastoplastic. The driving force acting on the pile-top is simplified to a triangular impact force. The kinematic equation of the pile-tip is established. From the one-dimensional wave equation, the movements of the pile-tip and pile-top are determined. The rebound at the pile-top can be written in a very concise form. It is shown that the shaft resistance makes the rebound at the pile-top decrease. In particular, when the pile is very long or the soil around the pile is very stiff, the decrease is very obvious.  相似文献   

15.
研究了不同树脂加入量和不同偶联剂添加量对人造石英石的弯曲强度和冲击韧性的影响,并研究了不同化学溶液对人造石英石的腐蚀作用,采用SEM对样品的断口形貌进行分析。结果表明,当树脂含量为10%、偶联剂添加量为1%时,试样的弯曲强度和冲击韧性分别达到了44.58MPa和10.92 kJ.m-2.5%盐酸溶液、10%氢氧化钠溶液和饱和碳酸钠溶液对人造石英石均有一定的腐蚀作用,其中氢氧化钠溶液的腐蚀作用最强.  相似文献   

16.
INTRODUCTIONIthadbeenrecognizedthatduringpiledriv ingthereboundofapile topgivesmoreinforma tionaboutresistancethanthepenetration (Chenetal.,1 996;Chenetal.,1 997;Utoetal.,1 992 ) .ThedevelopmentofthetheoreticalmodelofthepointresistanceobtainedfromPD andPDA measuremen…  相似文献   

17.
To study the bending strength of mass concrete under dynamic loading, the pure bending zone of three-graded concrete beam is considered as a three-phase composite composed of matrix, aggregate and interface between them on meso-level. Dynamic constitutive model considering strain-rate strengthening effect and damage softening effect is adopted to describe the cocrete and meso-element's damage. The failure mechanisms of beam under impact loading, triagle wave load, dynamic load coupling with initial static loading were simulated by using displacement-controlled FEM. Furthermore, stress-strain curve of the specimens and their dynamic bending strength were obtained. The results obtained from numerical simulation agreed well with experimental data.  相似文献   

18.
为了避免数控折弯机加工板材工件时的表面压痕发生,实验中从板材工件的折弯方式、材料硬度、凹模结构、选择机床与模具的精度4个方面来分析板材工件折弯时的产生表面压痕的原因。结果表明,通过使用防压痕胶垫、单V凹模防压痕胶套、块状优力胶+AT垫衬、硬质橡胶凹模和无压痕折弯凹模的方法来解决数控折弯时工件表面的压痕,达到产品质量要求。  相似文献   

19.
There is growing concern for corrosion damage in reinforced concrete structures with several decades’ service. Pullout tests and beam tests were carried out to study the effect of reinforcement corrosion on the bond behavior and bending strength of reinforced concrete beams. The bond strength of plain bars and concrete initially increases with increasing corrosion, then declines. The turning point depends on the cracking of the concrete cover. The bond strength of deformed bars and concrete increases with corrosion up to a certain amount, but with progressive increase in corrosion, the bond strength decreases, and the cracking of the concrete cover seems to have no effect on the bond strength. On the basis of test data, the bond strength coefficient recommended here, which, together with the bond strength of uncorroded steel bars and concrete, can be used to easily calculate the bond strength of corroded steel bars and concrete. The bond strength coefficient proposed in this paper can be used to study the bond stress-slip relationship of corroded steel bars and concrete. The bending strength of corroded reinforced concrete beams declines with increasing reinforcement corrosion. Decreased bending strength of corroded RC beam is due to reduction in steel bar cross section, reduction of yield strength of steel bar, and reduction of bond capacity between steel bar and concrete. Project supported by Cao Guanbiao Key Technology Development Founding of Zhejiang University and Construction Ministry of China.  相似文献   

20.
INTRODUCTIONThereisgrowingconcernforcorrosiondam ageinreinforcedconcrete (RC)structureswithseveraldecades’service.Thereinforcementcor rosionofRCconstructionsprobablyisthemostsignificantproblemandoutweighsotherformsofdeterioration .StudiesbyPeattieetal.( 1 9…  相似文献   

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