受冲击格构式钢拱弹塑性失稳数值模拟与试_验研究毕业论文

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1、学位论文受冲击格构式钢拱弹塑性失稳数值模拟与试验研究StudyonElastic-plasticBuckingofSteelLatticeArchAffectedbyImpact:SimulationandExperiment本文首先使用ABAQUS/Explicit模拟了刚体横向冲击弹塑性格构式钢拱的过程，研究了各种因素对冲击响应的影响,得出：随着冲击速度的增加，刚体块嵌入格构拱拱顶钢管深度逐渐增大，冲击荷载最大峰值和冲击接触时间亦显著增大；随着质量比的增加，刚体块嵌入深度和冲击荷载最大峰值逐渐减小，接触时间增

2、大；随着矢跨比的增大，冲击荷载最大峰值和接触时间逐渐减小，刚体块嵌入深度增大；随着格构拱跨度的增大，冲击荷载最大峰值、接触时间和刚体块嵌入深度都逐渐增大；随着格构拱壁厚的增大，冲击荷载最大峰值逐渐增大，刚体块嵌入深度和接触时间逐渐减小。本文通过分析刚体冲击弹塑性格构式钢拱过程，提出了基于整体变形和内能判断弹塑性格构拱动力屈曲的判别准则。根据判别准则得出：随着冲击速度和刚体质量的增大，屈曲时间减小；随着刚体块的质量增大，临界冲击速度减小，当刚体块质量较大时，临界屈曲速度变化较小。采用应变电测技术对格构式钢拱在冲击作

3、用下的动力响应进行试验研究，发现格构式钢拱在落锤的冲击作用下结构破坏形式有两种情况，分别为：（1）支座处破坏；（2）弹塑性大变形破坏。在两种破坏形式下结构均发生整体失稳，且为平面外失稳。关键词：格构式钢拱，冲击荷载，接触时间，动力屈曲，试验研究IIIAbstractThispaperfirstlyusedABAQUS/Explicittosimulatetheprocessofelastic-plasticsteellatticearchtransverselyimpactedbyrigidbody,andthe

4、impactresponseeffectedbyvariousfactorswasstudied.Themainconclusionsareasfollows:whenthevelocityofrigidbodyisincreasing,thedepthembeddedbyrigidbodyinsteeltubeofthelatticearchvaultchangeslarger,theimpactloadpeakvaluechangesgreater,thecontacttimepresentsansignif

5、icantincrease;withtheincreaseofmassratio,namelythequalityoftherigidblockissmaller,thedepthembeddedbyrigidbodyinsteeltubeofthelatticearchvaultandtheimpactloadpeakvaluechangesmaller,thecontacttimechangesshorter;withtheincreaseofrise-to-spanratio,theimpactloadpe

6、akvalueandthecontacttimehavedecreased,thedepthembeddedbyrigidbodychangesgreater;withtheincreaseoflatticearchspan,theimpactloadpeakvalue,thecontacttimeandthedepthembeddedbyrigidbodyallhavedecreased;withtheincreaseoflatticearchwallthickness,thecontacttimeandthe

7、depthembeddedbyrigidbodyhavedecreased,theimpactloadpeakvaluechangesgreater.Andthepaperanalyzedtheconclusionsinconsiderationoftheplasticdeformationandtheplasticdissipationenergy.Throughanalyzingtheprocessofelastic-plasticlatticearchimpactedbytherigidbody,thepa

8、perproposedthedynamicbucklingjudgmentcriterionbasedontheoveralldeformationandtheinternalenergy.Accordingtothejudgmentcriterion,themainconclusionsareasfollows:whenthevelocityofrigidbodyort