This paper numerically evaluates the effect of the crack position on the ultimate strength of stiffened panels.Imperfections such as notches and cracks in aged marine stiffened panels can reduce their ultimate strengt...This paper numerically evaluates the effect of the crack position on the ultimate strength of stiffened panels.Imperfections such as notches and cracks in aged marine stiffened panels can reduce their ultimate strength.To investigate the effect of crack length and position,a series of nonlinear finite element analyses were carried out and two cases were considered,i.e.,case 1 with thin stiffeners and case 2 with thick stiffeners.In both cases,the stiffeners have the same cross-section area.To have a basis for comparison,the intact panels were modeled as well.The cracks and notches were in the longitudinal and transverse direction and were assumed to be in the middle part of the panel.The cracks and notches were assumed to be through the thickness and there is neither crack propagation nor contact between crack faces.Based on the numerical results,longitudinal cracks affect the behavior of the stiffened panels in the postbuckling region.When the stiffeners are thinner,they buckle first and provide no reserved strength after plate buckling.Thus,cracks in the stiffeners do not affect the ultimate strength in the case of the thinner stiffeners.Generally,when stiffeners are thicker,they affect the postbuckling behavior more.In that case,cracks in the stiffeners affect the buckling and failure modes of the stiffened panels.The effect of notch was also studied.In contrast to the longitudinal crack in stiffeners,a notch in the stiffeners reduces the ultimate strength of the stiffened panel for both slender and thick stiffeners.展开更多
本文采用有限元法与强度稳定综合理论(combined theory of strength and stability,CTSS)公式研究箱型梁的极限强度问题。揭示了有限元计算方法的不稳定性,结合Vasta的始屈弯矩法提出箱型梁结构的极限弯矩简化计算公式。通过两个箱型梁...本文采用有限元法与强度稳定综合理论(combined theory of strength and stability,CTSS)公式研究箱型梁的极限强度问题。揭示了有限元计算方法的不稳定性,结合Vasta的始屈弯矩法提出箱型梁结构的极限弯矩简化计算公式。通过两个箱型梁结构的实例计算表明,该公式的计算结果相对于试验结果的误差在10%以内,且与非线性有限元法相比有着简单、稳定的优势,可以为工程设计提供参考。展开更多
文摘This paper numerically evaluates the effect of the crack position on the ultimate strength of stiffened panels.Imperfections such as notches and cracks in aged marine stiffened panels can reduce their ultimate strength.To investigate the effect of crack length and position,a series of nonlinear finite element analyses were carried out and two cases were considered,i.e.,case 1 with thin stiffeners and case 2 with thick stiffeners.In both cases,the stiffeners have the same cross-section area.To have a basis for comparison,the intact panels were modeled as well.The cracks and notches were in the longitudinal and transverse direction and were assumed to be in the middle part of the panel.The cracks and notches were assumed to be through the thickness and there is neither crack propagation nor contact between crack faces.Based on the numerical results,longitudinal cracks affect the behavior of the stiffened panels in the postbuckling region.When the stiffeners are thinner,they buckle first and provide no reserved strength after plate buckling.Thus,cracks in the stiffeners do not affect the ultimate strength in the case of the thinner stiffeners.Generally,when stiffeners are thicker,they affect the postbuckling behavior more.In that case,cracks in the stiffeners affect the buckling and failure modes of the stiffened panels.The effect of notch was also studied.In contrast to the longitudinal crack in stiffeners,a notch in the stiffeners reduces the ultimate strength of the stiffened panel for both slender and thick stiffeners.
文摘本文采用有限元法与强度稳定综合理论(combined theory of strength and stability,CTSS)公式研究箱型梁的极限强度问题。揭示了有限元计算方法的不稳定性,结合Vasta的始屈弯矩法提出箱型梁结构的极限弯矩简化计算公式。通过两个箱型梁结构的实例计算表明,该公式的计算结果相对于试验结果的误差在10%以内,且与非线性有限元法相比有着简单、稳定的优势,可以为工程设计提供参考。
