摘要：本文建立了等截面梁纯弯曲振动时的非线性动力学方程；根据非线性动力学理论，对等截面梁系统的奇点分布和稳定性进行了研究；利用混沌动力学理论，得到了等截面梁纯弯曲振动时产生混沌的参数条件；依据该条件，对匀质等截面简支梁纯弯曲振动时产生混沌的参数条件进行了研究和分析，得出了产生混沌的参数分界线。
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Abstract: The nonlinear dynamics equation of a equal section beam under pure bending vibration was developed . According to theory of the nonlinear dynamics, the singular point and stability of the system was studied. Using theory of Chaos, the parameter condition of a equal section beam for occurred Chaos under pure bending vibration was explored. According to the parameter condition , the parameter condition of a equal section simply supported beam for occurred Chaos under pure bending vibration was studied., the parameter dividing line of occurred Chaos were obtained.