【摘要】 由于电液高频疲劳试验机采用传统的电液伺服阀难以达到较高的激振频率,为了解决这个问题,采用一种特殊结构的2D激振阀来控制液压缸,从而提高电液高频疲劳试验机的激振频率.该2D激振阀具有双运动自由度,控制阀芯旋转可实现激振频率控制,控制阀芯轴向运动可实现激振幅值控制.由于2D激振阀的转阀特性,无法引入一个偏置信号实现对激振中心平衡位置的偏置控制,因此在对称液压缸上并联一个数字伺服阀,通过改变数字伺服阀的开口大小和方向就可以实现激振器振动中心位置的偏置.基于电液高频疲劳试验机的工作原理设计其控制系统并做实验.实验表明:该电液高频疲劳试验机的控制系统可实现高达2 500 Hz的激振频率;谐振频率为980 Hz,在该频率可进行高频率、大载荷的疲劳实验.更多还原

【Abstract】 Electro-hydraulic high-frequency fatigue test machine can not have a high excitation frequency using traditional electro-hydraulic servo valve.To solve this problem a special 2D exciting valve is used to control hydraulic cylinder.The 2Dexcitation valve has dual freedom of movement.The excitation frequency control can be achieved by controlling spool rotation,and the excitation amplitude control can be achieved by controlling spool axial movement.Since the characteristics of the rotary valve of 2Dexcitation valve,a bias signal can not used to achieve the equilibrium position,therefore a digital servo valve is paralleled on the symmetrical cylinder,vibration center position can be controlled by changing the opening size and the opening direction of the digital servo valve.A control system is built based on the working theory of electrohydraulic high-frequency fatigue test machine.The results of experiments shows that this control system can achieve excitation frequency up to 2 500Hz;the resonant frequency is 980 Hz which can be used in high-frequency,large load fatigue test.更多还原