In this paper a method based on a line-spring model was proposed to analyze approximately vibration responses of cracked beams. The method is conjunction with the Euler-Bernoulli beam theory, modal analysis and fractu...In this paper a method based on a line-spring model was proposed to analyze approximately vibration responses of cracked beams. The method is conjunction with the Euler-Bernoulli beam theory, modal analysis and fracture mechanics principle was applied to derive a characteristic equation for the cracked beam vibration. As application examples, natural frequency responses for a cracked hinged-hinged beam and a cracked cantilever beam were examined. It was shown that the present solutions obtained are quite in agreement with the solutions or experimental results in available references.展开更多
A new method based on a modified line-spring model is developed for evaluating the natural frequencies of vibration of a cracked beam.This model in conjunction with the Euler-Bernoulli beam theory,modal analysis and l...A new method based on a modified line-spring model is developed for evaluating the natural frequencies of vibration of a cracked beam.This model in conjunction with the Euler-Bernoulli beam theory,modal analysis and linear elastic fracture mechanics is applied to obtain an approximate characteristic equation of a cracked hinged-hinged beam.By solving this equation the natural frequencies are determined for different crack lengths in different positions.The results show good agreement with the solutions through finite element analysis.The present method may be extended to analyze other cracked complicated structures with various boundary conditions.展开更多
因四点弯曲梁跨中裂缝截面附近处于纯弯段,故其从理论上更符合Ι型断裂模式。基于此,该文通过开展跨中带缝的四点弯曲梁试验,将荷载作用下的四点弯曲梁纯弯曲段等效为纯弯曲梁,基于线性叠加原理给出了计算混凝土四点弯曲梁双K断裂参数...因四点弯曲梁跨中裂缝截面附近处于纯弯段,故其从理论上更符合Ι型断裂模式。基于此,该文通过开展跨中带缝的四点弯曲梁试验,将荷载作用下的四点弯曲梁纯弯曲段等效为纯弯曲梁,基于线性叠加原理给出了计算混凝土四点弯曲梁双K断裂参数的计算公式,并研究了不同初始缝高比(0.2、0.3、0.4、0.5及0.6)对四点弯曲梁双K断裂参数的影响,结果表明:随着初始缝高比的增大,试件起裂荷载Pini,最大荷载Pmax及相对临界有效裂缝扩展长度(ac-a0)/H均逐渐减小;起裂断裂韧度ini IC K和失稳断裂韧度un IC K基本保持不变。可见,四点弯曲梁可以用于研究混凝土的双K断裂参数。展开更多
文摘In this paper a method based on a line-spring model was proposed to analyze approximately vibration responses of cracked beams. The method is conjunction with the Euler-Bernoulli beam theory, modal analysis and fracture mechanics principle was applied to derive a characteristic equation for the cracked beam vibration. As application examples, natural frequency responses for a cracked hinged-hinged beam and a cracked cantilever beam were examined. It was shown that the present solutions obtained are quite in agreement with the solutions or experimental results in available references.
文摘A new method based on a modified line-spring model is developed for evaluating the natural frequencies of vibration of a cracked beam.This model in conjunction with the Euler-Bernoulli beam theory,modal analysis and linear elastic fracture mechanics is applied to obtain an approximate characteristic equation of a cracked hinged-hinged beam.By solving this equation the natural frequencies are determined for different crack lengths in different positions.The results show good agreement with the solutions through finite element analysis.The present method may be extended to analyze other cracked complicated structures with various boundary conditions.
文摘因四点弯曲梁跨中裂缝截面附近处于纯弯段,故其从理论上更符合Ι型断裂模式。基于此,该文通过开展跨中带缝的四点弯曲梁试验,将荷载作用下的四点弯曲梁纯弯曲段等效为纯弯曲梁,基于线性叠加原理给出了计算混凝土四点弯曲梁双K断裂参数的计算公式,并研究了不同初始缝高比(0.2、0.3、0.4、0.5及0.6)对四点弯曲梁双K断裂参数的影响,结果表明:随着初始缝高比的增大,试件起裂荷载Pini,最大荷载Pmax及相对临界有效裂缝扩展长度(ac-a0)/H均逐渐减小;起裂断裂韧度ini IC K和失稳断裂韧度un IC K基本保持不变。可见,四点弯曲梁可以用于研究混凝土的双K断裂参数。
