The steady-state response of a strongly nonlinear system often has multiple solutions under harmonic excitation, which includes both multiple response amplitudes and multiple phases. Taking advantage of the force dropout phenomenon of electrodynamic shakers near resonance, a fixed frequency test method was proposed previously to measure the multivalued amplitude curves continuously. This method is further developed in this paper to measure the multivalued phase curves, which represent the degree by which the response lags the excitation, synchronously and continuously using the input voltage as the continuation parameter. The multivalued phase curve of a strongly nonlinear system is found to contain abundant information and is closely related to the multivalued amplitude curve. The phases of the response and excitation of a strongly nonlinear system are extracted accurately by the period resampling technique usually used in rotor dynamics tests. The phase shift of the electrodynamic shaker is large when the force drops out near resonance in fixed frequency tests. This phenomenon is used to measure the multivalued phase curves, together with the multivalued amplitude curves. An experimental test of a strongly nonlinear single degree of freedom system is used to demonstrate this method. The evolution of the phase curves and the corresponding relationship with the amplitude curves in fixed frequency tests are discussed. Numerical simulation is also undertaken to validate this method.

强非线性系统的稳态响应在谐波激励下通常具有多个解决方案，其中包括多个响应幅度和多个相位。利用电动振动器在共振附近的力下降现象，以前提出了一种固定频率测试方法来连续测量多值振幅曲线。本文进一步开发了该方法，以测量多值相位曲线，该曲线表示使用输入电压作为连续参数，同步且连续地响应滞后激励的程度。发现强非线性系统的多值相位曲线包含大量信息，并且与多值幅度曲线密切相关。通过通常在转子动力学测试中使用的周期重采样技术，可以精确地提取强非线性系统的响应和励磁相位。在固定频率测试中，当力在共振附近消失时，电动振动台的相移就会很大。该现象用于测量多值相位曲线以及多值幅度曲线。一个强非线性单自由度系统的实验测试用来证明这种方法。讨论了固定频率测试中相位曲线的演变以及与幅度曲线的对应关系。还进行了数值模拟以验证该方法。在固定频率测试中，当力在共振附近消失时，电动振动台的相移就会很大。该现象用于测量多值相位曲线以及多值幅度曲线。一个强非线性单自由度系统的实验测试用来证明这种方法。讨论了固定频率测试中相位曲线的演变以及与幅度曲线的对应关系。还进行了数值模拟以验证该方法。在固定频率测试中，当力在共振附近消失时，电动振动台的相移就会很大。该现象用于测量多值相位曲线以及多值幅度曲线。一个强非线性单自由度系统的实验测试用来证明这种方法。讨论了固定频率测试中相位曲线的演变以及与幅度曲线的对应关系。还进行了数值模拟以验证该方法。讨论了固定频率测试中相位曲线的演变以及与幅度曲线的对应关系。还进行了数值模拟以验证该方法。讨论了固定频率测试中相位曲线的演变以及与幅度曲线的对应关系。还进行了数值模拟以验证该方法。