中文摘要：

为在一根 Timoshenko 横梁的裂缝察觉的一种其他的技术在这篇论文基于第一反反响的频率被介绍。不同于自然频率，反反响的频率是一个本地参数而非结构的一个全球参数，因此，建议技术能被用来定位结构的缺点。泛音力量基于 Timoshenko 横梁明确的表达刺激的一根击碎的横梁的阻抗分析被调查。以便由于裂缝描绘本地断绝，一个旋转春天模型基于破裂力学被建议为裂缝建模。随后，建议方法被一根简单地支持的横梁的一个数字例子与一个裂缝验证。反反响的频率上的裂缝尺寸的效果被调查。简单地支持的横梁的裂缝的位置被反共振技术也决定。建议技术进一步被用于“污染”的反反响的频率检测裂缝损坏，它被把 1-3% 噪音加到计算数据获得。建议技术从环境噪音有效、免费，这被发现。最后，试验性的研究被执行，它进一步验证建议裂缝鉴定技术的有效性。

英文摘要：

An alternative technique for crack detection in a Timoshenko beam based on the first anti-resonant frequency is presented in this paper. Unlike the natural frequency, the anti-resonant frequency is a local parameter rather than a global parameter of structures, thus the proposed technique can be used to locate the structural defects. An impedance analysis of a cracked beam stimulated by a harmonic force based on the Timoshenko beam formulation is investigated. In order to characterize the local discontinuity due to cracks, a rotational spring model based on fracture mechanics is proposed to model the crack. Subsequently, the proposed method is verified by a numerical example of a simply-supported beam with a crack. The effect of the crack size on the anti-resonant frequency is investigated. The position of the crack of the simply-supported beam is also determined by the anti-resonance technique. The proposed technique is further applied to the ＂contaminated＂ anti-resonant frequency to detect crack damage, which is obtained by adding 1-3% noise to the calculated data. It is found that the proposed technique is effective and free from the environment noise. Finally, an experimental study is performed, which further verifies the validity of the proposed crack identification technique.