Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pi...Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pits,or uneven surfaces,where localized stress concentrations are readily induced.This study conducted a series of laboratory desiccation tests on slurry samples to investigate the initiation and propagation of desiccation cracks in the presence of varying types and quantities of surface defects.Digital image correlation(DIC)technology was employed to monitor the strain and displacement fields on the soil surface during the desiccation process.The results reveal that strain and displacement data derived from DIC can precisely predict the initiation sites and propagation directions of desiccation cracks.In samples with internal defects,cracks predominantly propagate through the defect,whereas external defects tend to initiate cracks along their edges.In samples with multiple defects,Y-shaped crack patterns generally form initially,followed by T-shaped and straight cracks,driven by the evolving stress field.The dynamic interplay between crack formation and tensile stress redistribution governs the initiation and propagation of desiccation cracks.展开更多
板结构的稳定性在船舶设计和强度校核中占据重要地位。为研究船体薄板的剪切稳定性,本文设计画框式夹具对方形薄板进行面内剪切屈曲试验,试验中采用三维数字图像相关法(3 Dimensions Digital Image Correlation,简称3D-DIC),获得了载荷...板结构的稳定性在船舶设计和强度校核中占据重要地位。为研究船体薄板的剪切稳定性,本文设计画框式夹具对方形薄板进行面内剪切屈曲试验,试验中采用三维数字图像相关法(3 Dimensions Digital Image Correlation,简称3D-DIC),获得了载荷-端部伸长率曲线、全场位移/应变等力学响应信息。载荷-端部伸长率关系揭示了薄板在面内剪切工况下的承载特性,确定了屈曲失稳临界载荷;通过分析薄板在典型时刻的位移场、应变场信息,发现薄板的法向变形会随面内剪切载荷增加而增大。薄板失稳后,沿垂直对角线存在对称分布的三个半波,内部波幅大于外部波幅,应变波形和云图在后屈曲过程中会趋于稳定。通过分析薄板关键点的法向位移和米塞斯应变随时间的响应曲线,提出并验证了一种识别面内受剪薄板屈曲失稳的新方法。本文为船用薄板面内剪切稳定性的试验研究和力学行为分析等提供了有益参考。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42525201,42230710,42407521).
文摘Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pits,or uneven surfaces,where localized stress concentrations are readily induced.This study conducted a series of laboratory desiccation tests on slurry samples to investigate the initiation and propagation of desiccation cracks in the presence of varying types and quantities of surface defects.Digital image correlation(DIC)technology was employed to monitor the strain and displacement fields on the soil surface during the desiccation process.The results reveal that strain and displacement data derived from DIC can precisely predict the initiation sites and propagation directions of desiccation cracks.In samples with internal defects,cracks predominantly propagate through the defect,whereas external defects tend to initiate cracks along their edges.In samples with multiple defects,Y-shaped crack patterns generally form initially,followed by T-shaped and straight cracks,driven by the evolving stress field.The dynamic interplay between crack formation and tensile stress redistribution governs the initiation and propagation of desiccation cracks.
文摘板结构的稳定性在船舶设计和强度校核中占据重要地位。为研究船体薄板的剪切稳定性,本文设计画框式夹具对方形薄板进行面内剪切屈曲试验,试验中采用三维数字图像相关法(3 Dimensions Digital Image Correlation,简称3D-DIC),获得了载荷-端部伸长率曲线、全场位移/应变等力学响应信息。载荷-端部伸长率关系揭示了薄板在面内剪切工况下的承载特性,确定了屈曲失稳临界载荷;通过分析薄板在典型时刻的位移场、应变场信息,发现薄板的法向变形会随面内剪切载荷增加而增大。薄板失稳后,沿垂直对角线存在对称分布的三个半波,内部波幅大于外部波幅,应变波形和云图在后屈曲过程中会趋于稳定。通过分析薄板关键点的法向位移和米塞斯应变随时间的响应曲线,提出并验证了一种识别面内受剪薄板屈曲失稳的新方法。本文为船用薄板面内剪切稳定性的试验研究和力学行为分析等提供了有益参考。
