CAJ | 학술논문

球基轻质多孔材料的单球基元有多种构建形式,四点焊接金属空心球(Metal Hollow Sphere, MHS)是其中一种特殊类型.对四点焊接的金属空心球进行了单轴压缩实验.由于其中某些空心球在焊接时出现了孔洞,故分别做了完整和焊接出现孔洞的两种情况下的多组实验,得出了焊缝与水平面夹角θ成不同角度时压缩的名义应力-应变曲线.对比了各种夹角θ情况下的弹性模量、屈曲应力.根据实验结果,得出了θ=45度时其首次屈曲应力最大的结论.通过简化模型给出了其原因,并定性地分析了二次屈曲的问题.另外,结合实验现象分析了金属空心球在压缩时的屈服和屈曲过程.同时,对焊接完整和焊接出现孔洞两种情况进行了对比,发现有孔洞时其首次屈曲应力更低.以上结果对球基多孔材料的研究具有参考价值.
구기경질다공재료적단구기원유다충구건형식,사점한접금속공심구(Metal Hollow Sphere, MHS)시기중일충특수류형.대사점한접적금속공심구진행료단축압축실험.유우기중모사공심구재한접시출현료공동,고분별주료완정화한접출현공동적량충정황하적다조실험,득출료한봉여수평면협각θ성불동각도시압축적명의응력-응변곡선.대비료각충협각θ정황하적탄성모량、굴곡응력.근거실험결과,득출료θ=45도시기수차굴곡응력최대적결론.통과간화모형급출료기원인,병정성지분석료이차굴곡적문제.령외,결합실험현상분석료금속공심구재압축시적굴복화굴곡과정.동시,대한접완정화한접출현공동량충정황진행료대비,발현유공동시기수차굴곡응력경저.이상결과대구기다공재료적연구구유삼고개치.
Single sphere element of lightweight cellular material has many structure types. Four point welded thin-walled metallic hollow sphere (MHS) composed by two hemisphere shells is a sort of them. Uniaxial compression experiment for thin-walled MHS was carried out. Multiple experiments include whole sphere and sphere with cracks due to some spheres have a few cracks in the shell equatorial plane after welding. Then, the nominal compression stress-strain curves corresponding to different included anglesθ between horizontal plane and welding line were plotted. Elastic modulus and the first buckling stress corresponding different anglesθwere compared. It is concluded that the first buckling stress is the maximum when angleθ equals 45°based on experimental results. The interpretation of above conclusion and the second buckling process are qualitatively analyzed in this paper. Yield and buckling in compression process were analyzed combining with experimental phenomena. In addition, the comparison of first buckling stress between the whole MHS and MHS with some cracks was carried out. It is found that the first buckling stress of spheres with cracks is lower. These results have valuable reference for lightweight cellular material study.