为了对扩展裂纹进行止裂,对SCSC构型试件进行改进,提出V型边界侧开单裂纹半孔板(V-shape boundary single cleavage semi circle specimen,VB-SCSC)构型试件,该试件具有V型的底部边界,在冲击载荷下产生倾斜向上的压缩波,该压缩波的水平...为了对扩展裂纹进行止裂,对SCSC构型试件进行改进,提出V型边界侧开单裂纹半孔板(V-shape boundary single cleavage semi circle specimen,VB-SCSC)构型试件,该试件具有V型的底部边界,在冲击载荷下产生倾斜向上的压缩波,该压缩波的水平分量对扩展裂纹具有压缩作用,进而对扩展裂纹进行止裂。实验采用中低速落锤冲击实验装置进行,利用裂纹扩展计(crack propagation gauge,CPG)测试裂纹的起裂及扩展时间,同时测试裂纹的扩展速度。采用3种V型底部的夹角,即120°,150°及180°(平的底部),进行实验研究,发现前2种试件均具有止裂功能,并用有限差分软件AUTODYN进行了模拟计算,其结果与实验结果基本一致。利用有限元软件ABAQUS计算裂纹的动态应力强度因子,并通过普适函数进行修正,最后通过裂纹起裂时间及扩展时间确定裂纹的动态断裂韧度。结果表明120°VB-SCSC构型试件具有较好的止裂功能,适合于裂纹动态扩展行为研究及动态断裂韧度的测试;动态扩展韧度与裂纹的扩展速度成反比。展开更多
A microporous supramolecular framework with high water and thermal stability can selectively absorb water molecules over methanol or ethanol due to the suitable channels.The model separation test on columns shows that...A microporous supramolecular framework with high water and thermal stability can selectively absorb water molecules over methanol or ethanol due to the suitable channels.The model separation test on columns shows that an ultra-pure ethanol(99.9%)can be obtained from the mixture of ethanol/water(95:5).Additionally,after refluxing the desolvated sample in 95%ethanol at 60℃for 5 h,the purity of ethanol rises up to 97.43%,which is obviously higher than 96.56%for 4 A molecular sieves.展开更多
文摘为了对扩展裂纹进行止裂,对SCSC构型试件进行改进,提出V型边界侧开单裂纹半孔板(V-shape boundary single cleavage semi circle specimen,VB-SCSC)构型试件,该试件具有V型的底部边界,在冲击载荷下产生倾斜向上的压缩波,该压缩波的水平分量对扩展裂纹具有压缩作用,进而对扩展裂纹进行止裂。实验采用中低速落锤冲击实验装置进行,利用裂纹扩展计(crack propagation gauge,CPG)测试裂纹的起裂及扩展时间,同时测试裂纹的扩展速度。采用3种V型底部的夹角,即120°,150°及180°(平的底部),进行实验研究,发现前2种试件均具有止裂功能,并用有限差分软件AUTODYN进行了模拟计算,其结果与实验结果基本一致。利用有限元软件ABAQUS计算裂纹的动态应力强度因子,并通过普适函数进行修正,最后通过裂纹起裂时间及扩展时间确定裂纹的动态断裂韧度。结果表明120°VB-SCSC构型试件具有较好的止裂功能,适合于裂纹动态扩展行为研究及动态断裂韧度的测试;动态扩展韧度与裂纹的扩展速度成反比。
基金support from the National Key Research and Development Program of China(No.2017YFA0700102)the National Natural Science Foundation of China(Nos.21871266 and 21731006)+1 种基金the Key Research Program of Frontier Science CAS(No.QYZDY-SSW-SLH025)Youth Innovation Promotion Association CAS.
文摘A microporous supramolecular framework with high water and thermal stability can selectively absorb water molecules over methanol or ethanol due to the suitable channels.The model separation test on columns shows that an ultra-pure ethanol(99.9%)can be obtained from the mixture of ethanol/water(95:5).Additionally,after refluxing the desolvated sample in 95%ethanol at 60℃for 5 h,the purity of ethanol rises up to 97.43%,which is obviously higher than 96.56%for 4 A molecular sieves.
