振动与冲击
振動與遲擊
진동여충격
JOURNAL OF VIBRATION AND SHOCK
2014年
15期
144-149
,共6页
下承式钢管混凝土刚架系杆拱桥%吊杆%断裂%动力分析
下承式鋼管混凝土剛架繫桿拱橋%弔桿%斷裂%動力分析
하승식강관혼응토강가계간공교%조간%단렬%동력분석
rigid-frame tied through concrete-filled steel tubular (CFST)arch bridge%cable%loss%dynamic analy-sis
以一座下承式钢管混凝土刚架系杆拱桥为研究对象,采用 ANSYS /LS -DYNA 软件建立有限元模型,通过接触碰撞的方式进行吊杆断裂的模拟,分析吊杆断裂前后拱桥各结构构件受力状态的变化,判断结构可能发生的破坏形态。分析结果表明,吊杆断裂过程中吊杆、钢管混凝土拱肋和桥道系均会受到断索冲击的作用;与断裂吊杆相邻的吊杆受到断索冲击的作用最大,其轴力变化量为初始轴力的3倍以上,需要考虑由于吊杆断裂过程中产生的大于静力响应的动力作用;吊杆断裂对主梁产生的影响远大于拱肋,拱肋内力变化较小;由于横梁两侧与纵梁连接处焊缝强度不足发生破坏可能导致桥道系局部坍塌。
以一座下承式鋼管混凝土剛架繫桿拱橋為研究對象,採用 ANSYS /LS -DYNA 軟件建立有限元模型,通過接觸踫撞的方式進行弔桿斷裂的模擬,分析弔桿斷裂前後拱橋各結構構件受力狀態的變化,判斷結構可能髮生的破壞形態。分析結果錶明,弔桿斷裂過程中弔桿、鋼管混凝土拱肋和橋道繫均會受到斷索遲擊的作用;與斷裂弔桿相鄰的弔桿受到斷索遲擊的作用最大,其軸力變化量為初始軸力的3倍以上,需要攷慮由于弔桿斷裂過程中產生的大于靜力響應的動力作用;弔桿斷裂對主樑產生的影響遠大于拱肋,拱肋內力變化較小;由于橫樑兩側與縱樑連接處銲縫彊度不足髮生破壞可能導緻橋道繫跼部坍塌。
이일좌하승식강관혼응토강가계간공교위연구대상,채용 ANSYS /LS -DYNA 연건건립유한원모형,통과접촉팽당적방식진행조간단렬적모의,분석조간단렬전후공교각결구구건수력상태적변화,판단결구가능발생적파배형태。분석결과표명,조간단렬과정중조간、강관혼응토공륵화교도계균회수도단색충격적작용;여단렬조간상린적조간수도단색충격적작용최대,기축력변화량위초시축력적3배이상,수요고필유우조간단렬과정중산생적대우정력향응적동력작용;조간단렬대주량산생적영향원대우공륵,공륵내력변화교소;유우횡량량측여종량련접처한봉강도불족발생파배가능도치교도계국부담탑。
Taking a rigid-frame tied through CFST arch bridge as a study object,a finite element model was built with the software ANSYS /LS-DYNA.The process of its cable loss was simulated with the contact-impact method.The variation of the internal forces of its different structure members before and after cable loss was analyzed to determine the potential failure mode of the structure.The results showed that cables,CFST arch ribs and deck slabs all bear a impact due to a cable loss;among them,the influence of the cable loss on the adjacent cables is the largest and the variation of their axial forces exceeds three times of their initial values;therefore,the action of the dynamic force which is far greater than the static force action during the cable loss should be considered;the influence of cable loss on the main girder is significantly greater than that on the arch ribs;the local collapse of the deck system may occur due to the insufficient strength of the weld connection between transverse beams and longitudinal ones.