碳纤维布在某电厂冷却塔加固中的应用

简单介绍了碳纤维加固技术的原理和优点,以某电厂冷却塔加固工程为例,阐述了碳纤维布加固技术的施工工艺及注意事项,为类似工程积累了施工经验。     

碳纤维布在中小跨径桥梁上部结构加固中应用

结合具体工程实例,介绍了碳纤维布加固中小跨径桥梁上部结构的处治方案和加固机理,分别阐述了该工艺的计算方法、设计要点、材料及施工方法等,对于同类桥梁的加固具有指导作用和推广价值。     

外贴碳纤维布在混凝土结构加固中的应用

阐述了碳纤维布的性能及该材料在混凝土结构加固技术中的应用,结合工程实践总结了加固施工工艺和技术要点,并进行了检验及验收,证实了碳纤维布加固技术的可行性。     

二次受力下碳纤维布加固钢筋混凝土梁的分析

以有限元软件ANSYS为分析工具对二次受力状态下碳纤维布加固钢筋混凝土梁的受弯承载力进行了非线性分析,并与试验值进行对比,结果表明：ANSYS计算值与试验值吻合较好,初始荷载的存在会降低碳纤维布加固的效果,建议在实际加固工程中尽可能卸载,以保证加固效果。     

碳纤维加固钢筋混凝土梁受弯性能非线性有限元分析

研究混凝土、受拉钢筋和CFRP在开裂、屈服、破坏各阶段的工作状态和受力特点,对认识CFRP加固机理和性能有着重要意义。应用ANSYS建立碳纤维加固钢筋混凝土梁有限元模型,利用单元生死技术模拟CFRP的不同工作状态,对试件梁开裂、屈服、破坏全过程进行非线性有限元分析。分析表明:在钢筋屈服后,CFRP加固钢筋混凝土梁在后期抗弯刚度、延性和极限承载能力方面均有增强;在结构承受较大初始荷载情况下,二次受力问题对加固梁的抗弯刚度、极限承载能力、延性存在一定影响;由于CFRP是在钢筋进入屈服阶段,应力停止增长后才发挥巨大作用,二次受力时的加固也能取得较好效果;分析结果与实测数据吻合。     

Free-form curves cutting using flexible circular saw

A flexible circular saw, which can be used in a novel machining process for high-speed carbon fiber-reinforced plastic (CFRP) plate cutting, was developed. In this process, the saw is deflected like a bowl-like shape. A cross-section of the saw body then forms a circular arc. A curved line can therefore be cut without interference by the bowl-like deflection. In addition, the radius of the cross-section of the saw body can be controlled by adjusting the deflection. This process therefore allows curves to be cut with a varied radius using a single saw. This process can carry out high-speed curved-line cutting with a feed rate of 3 m/min on a CFRP plate. However, it is difficult to cut free-form curves using a flexible circular saw. Therefore, in this research, a new technique that can cut free-form curves using a flexible circular saw was proposed. Then, a cutting test applying the technique was carried out.     

碳纤维复合材料T型铣刀的切槽试验研究

针对碳纤维复合材料(CFRP)的齿槽加工,提出采用T型铣刀切制齿槽。以平纹CFRP为研究对象,通过齿槽的切削试验,分析切削力和残余因子。试验表明:切削力随着切削速度vc的增大而减小,但切削速度vc大于245 m/min时,进给方向切削力Fx将逐渐增大;与切削速度vc相比,进给速度vf对残余因子Fb的影响更大,随着它的增大,残余因子Fb平均减小46.63%;顺铣时的切削力和残余因子比逆铣时的明显要小。研究结果为CFRP的齿槽铣削加工提供了技术指导。     

排子河渡槽病险成因分析

针对湖北省大中型灌区混凝土渡槽普遍存在老损率高、破坏严重、制约灌溉效益发挥的现象,以引丹灌区排子河渡槽为研究对象,探讨渡槽出现病险的原因。通过大型有限元分析软件ANSYS分析渡槽各种工况的运行情况。结果表明,若把水工结构中的肋形梁板结构计算模型应用到薄壁梁结构设计中,可能导致计算结果不可靠;将三维实体单元应用于渡槽的有限元分析中,可以最大限度地模拟原结构的实际受力情况。同时,介绍了碳纤维布在渡槽加固中的应用,实践证明用碳纤维布加固渡槽经济效益显著。     

基于CFRP板材施加预应力桥梁加固动力性能研究

采用CFRP板施加预应力是目前有效的桥梁加固技术。论文完整介绍了一座采用CFRP预应力板加固后的桥梁动力性能试验，包括结构模态、跑车试验、刹车试验和跳车试验，监测了结构动位移、动应变及相关冲击作用，证明了CFRP预应力板加固效果十分理想。相关结论和数据可为类似桥梁的动力试验提供参考。     

Repair method and residual bearing strength evaluation of a locally corroded plate girder at support

There is growing interest in the maintenance and repair of bridges according to the increase in their service time. Many corrosion problems have especially been reported in plate girder bridges in support regions because of their high moisture level due to the bad air circulation, sediments, deposition, rain water, and antifreeze penetration in the drainage-type expansion joint. In this study, CFRP repair of a plate girder with localized corrosion at its support was proposed, and this method was used to repair the locally corroded plate girder around its support to examine the applicability and effectiveness of the corrosion repair method using CFRP. FE analysis of the corroded plate girder model was carried out to clarify the residual bearing strength and failure mode due to the localized plate girder corrosion in the web and stiffener at the support region. The application of the CFRP repair method to the plate girder bridge with local corrosion at its support showed that such method can be useful for corroded bridges due to its rapid and simple application and the stress level improvement on the repaired corroded surface on account of the sectional reinforcement effect of the CFRP repair and the prevention of the corrosion progress in the plate girder. The evaluation of the residual bearing strength of the plate girder with local corrosion at its support showed that such strength was affected more by the corrosion related to the stiffener than by the local web corrosion at the support. Therefore, to prevent local corrosion of a plate girder at its support, the corrosion ratio of the stiffener must be considered more than that of the web, and a corroded stiffener must be repaired or reinforced ahead of a corroded web.