起重机金属结构裂纹的复合修复方法

摘要/Abstract

摘要： 针对起重机金属结构在长期疲劳交变载荷作用下易产生疲劳裂纹的问题，采用碳纤维复合材料（CFRP）加固止裂孔的方法对裂纹进行复合修复。建立不同载荷下止裂孔、CFRP以及复合修复的有限元模型，分析计算应力应变状态和应力集中系数；建立止裂孔打偏情况下复合修复的有限元模型，研究CFRP加固对止裂孔修复的影响；通过静拉伸强度试验，研究复合修复方法对损伤构件的修复效果，并与仿真结果进行对比，验证了CFRP与止裂孔复合修复这一技术的可行性。结果表明，复合修复方法相比于止裂孔及CFRP修复效果，不仅可以消除裂纹尖端的奇异性，减小名义应力，提高试件的承载能力，还可以弥补钻止裂孔修复焊缝裂纹的不足，为工程维修提供了参考。

关键词: 碳纤维复合材料, 止裂孔, 复合修复, 奇异性, 名义应力, 承载能力

Abstract: Crane metal constructions under long-term alternating loads were easy to produce fatigue cracks， a combination of CFRP and stop-hole was studied to rapair the cracks herein. Firstly， the finite element models of stop-hole， CFRP and composite repair were established， and the stress-strain states and stress concentration factors were analyzed. Then， the finite element model of composite repair with the stop-hole missing crack tips was built to study the effects of CFRP reinforcement on the repair of stop-hole. Finally， the effectiveness of composite repair for damaged members was studied by static tensile strength tests， the feasibility of this technology was verified through comparing the testing and simulation results. The results show that the composite repair method may eliminate the singularity of the crack tips， reduce the nominal stresses， improve the bearing capacities of the specimens， and make up for the weld cracks inadequacy of drilling stop holes， which provides an reference for engineering maintenances.

Key words: carbon fiber reinforced polymer （CFRP）, stop-hole, composite repair, singularity, nominal stress, bearing capacity

中图分类号:

TH2
TH17

孔璞萍;刘志平;周凯;毛艳飞. 起重机金属结构裂纹的复合修复方法[J]. 中国机械工程.

KONG Puping;LIU Zhiping;ZHOU Kai;MAO Yanfei. Composite Repair Method of Crane Metal Constructions[J]. China Mechanical Engineering.

参考文献

[1]CHEN N Z. A Stop-hole Method for Marine and Offshore Structures[J］.International Journal of Fatigue，2016，88（3）：49-57.
[2]FANNI M，FOUDA N，SHABARA M A N，et al. New Crack Stop Hole Shape Using Structure Optimizing Technique[J］.Ain Shams Engineering Journal，2015，6（3）：987-999.
[3]孙昌之. 起重机金属结构裂纹修复后再生裂纹的探讨[J］.起重运输机械，2000，2（1）：31-33.
SUN Changzhi. Exploration of Occurring of New Crack on Metal Structures of Cranes after Old Crack Was Repaired [J］.Hoisting and Conveying Machinery，2000，2（1）：31-33.
[4]张术宽，黄培彦，赵传宇．CFL加固受弯钢板中表面裂纹应力强度因子的数值分析[J］．华南理工大学学报（自然科学版），2012，40（4）：162-168.
ZHANG Shukuan，HUANG Peiyan，ZHAO Chuanyu. Numerical Analysis of Stress Intensity Factor of Surface Crack in Steel Plate Strengthened with CFL under Bending Load [J］.Journal of South China University of Technology （Natural Science Edition），2012，40（4）：162-168.
[5]EMDAD R，AL-MAHAIDI R. Effect of Prestressed CFRP Patches on Crack Growth of Centre-notched Steel Plates[J］.Composite Structures，2015，123（12）：109-122.
[6]赵传宇，黄培彦，罗毅．受拉FRP加固X80钢板中表面裂纹应力强度因子的数值分析[J］．华南理工大学学报（自然科学版），2013，41（8）：109-114.
ZHAO Chuanyu，HUANG Peiyan，LUO Yi. Numerical Analysis of Stress Intensity Factor of Surface Crack in X80 Steel Plate Strengthened with FRP under Tensile Load[J］.Journal of South China University of Technology （Natural Science Edition），2013，41（8）：109-114.
[7]COLOMBI P，FAVA G，SONZOGNI L. Fatigue Crack Growth in CFRP-strengthened Steel Plates[J］.Composites，2015，72（11）：87-96.
[8]吉伯海，袁周致远，刘天笳，等. 钢箱梁疲劳裂纹钻孔止裂修复的影响因素[J］.江苏大学学报（自然科学版），2016，37（1）：97-102.
JI Bohai，YUAN Zhouzhiyuan，LIU Tianjia，et al. Influencing Factors of Stop-hole Method for Fatigue Crack of Steel Box Girder [J］.Journal of Jiangsu University（Natural Science Edition），2016，37（1）：97-102.
[9]曹靖，王建国，完海鹰. CFRP加固钢结构吊车梁疲劳有限元分析及应用[J］. 合肥工业大学学报（自然科学版），2010，33（1）：85-88.
CAO Jing，WANG Jianguo，WAN Haiying. Finite Element Analysis of Fatigue of Steel Crane Beam Structures Reinforced with CFRP and Its Application[J］.Journal of Hefei University of Technology（Natural Science），2010，33（1）：85-88.
[10]KULYK V V，LENKOVS'KYI T M，OSTASH O P. Mode Ⅰ and Mode Ⅱ Cyclic Crack Resistance of Wheel Steel[J］.Strength of Materials，2017，49（2）：1-7.
[11]TSCHEGG E K. Mode Ⅲ and Mode I Fatigue Crack Propagation Behaviour under Torsional Loading[J］.Journal of Materials Science，1983，18（6）：1604-1614.
[12]LI H F，QIAN C F，YUAN Q B. Cracking Simulation of a Tubesheet under Different Loadings[J］.Theoretical & Applied Fracture Mechanics，2010，54（1）：27-36.
[13]王春华，张博宁. 桥式起重机箱形梁疲劳裂纹及其剩余寿命[J］.机械设计与研究，2014，30（4）：144-147.
WANG Chunhua，ZHANG Boning. The Box Beam Fatigue Crack and Residual Life of Bridge Crane[J］.Machine Design and Research，2014，30（4）：144-147.
[14]WU C，ZHAO X L，AL-MAHAIDI R，et al. Effects of CFRP Bond Locations on the Mode I Stress Intensity Factor of Centre-cracked Tensile Steel Plates[J］.Fatigue& Fracture of Engineering Materials&Structures，2012，36（2）：154-167.
[15]ZHOU Z，BHAMARE S，QIAN D. Ductile Fracture in Thin Sheet Metals： a FEM Study of the Sandia Fracture Challenge Problem Based on the Gurson-Tvergaard-Needleman Fracture Model[J］.International Journal of Fracture， 2014， 186（1）：185-200.