振动器作为可控震源的核心部件,其性能对可控震源输出信号的质量起着至关重要的作用.为了准确掌握可控震源振动器的模态特性,找到非激励振动的原因,根据有限元模态分析相关理论,建立了振动器-大地有限元模型,利用ANSYS Workbench软件对模型进行预应力模态分析,获得施加预应力后的振动器变形情况和前6阶固有频率以及相应的振型.有限元分析表明:在实际工作频宽内,振动器的主要振动形式是平板以上结构沿长轴和短轴的摆动以及以活塞杆为中心的扭转.针对有限元分析结果,进行了现场试验,试验结果与仿真分析一致,证明了有限元分析的正确性.研究表明,振动器共振会导致非激励性的摆动和扭转,这是振动器输出信号畸变的一个原因.研究结论为振动器结构设计和现场作业提供了理论指导.%As a core component of the vibroseis, vibrator has a crucial impact on the vibrator output signal quality. In order to accurately understand the modal characteristics of the vibroseis vibrator and figure out the cause of the non-excitation modal, finite element model of vibratorground was developed based on the theory of finite element modal analysis, and the pre-stress modal analysis was carried out by using ANSYS Workbench software. Deformation of vibrator under pre-stress condition, the first six natural frequencies and vibration modes of vibrator were obtained. Finite element analysis showed that the main vibration modes of the vibrator within the actual operating bandwidth were swinging along the long axis and short axis of the baseplate and twisting centered about the piston. Experimental verification was conducted according to the finite element analysis results. The experimental result was consistent with the simulation analysis, which verified the correctness of finite element analysis. Studies show that resonance of vibrator results in non-excitation of swinging and twisting, which is one of the causes of distortion of the vibrator output signal. Research provides theoretical guidance for structural design and field work of vibrator.
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