Dual-direction synchronous loading method for true-triaxial test apparatus

A dual-direction synchronous loading method for a true-triaxial test apparatus, comprising the following steps:

• Step S1, loading a sample and adjusting the sample at a center of a sample box and a rigid loading frame;
• Step S2, setting parameters and sending action instructions through a computer control panel;
• and
• Step S3, by a PID controller, collecting load signals collected by each sensor, and coordinating a size of triaxial dual-direction loading loads to realize a single instruction dual-direction synchronous loading,
• wherein Step S3 specifically comprises:
• in order to achieve the single instruction dual-direction synchronous loading, connecting two loading actuators on a same axis in series by an iADA voltage amplification module and an iDCA signal integration module;
• sending loading instructions by a computer to one of the two loading actuators on the same axis;
• wherein at this time, a PID controller I receives an electrical signal I, and controls an electro-hydraulic servo valve to activate the loading actuator to perform a loading action, and the sensor records data in real-time and feedbacks the data to the PID controller I, thereby achieving a closed-loop control of one direction on the same axis;
• at the same time, the electrical signal I is amplified into an electrical signal II by the iADA voltage amplification module, and the electrical signal II is integrated by the iDCA signal integration module and then transmitted to a PID controller II;
• the PID controller II controls another electro-hydraulic servo valve to activate another loading actuator on the same axis to perform another loading action;
• the other sensor records data in real-time and feedbacks the data to the PID controller II, thereby achieving a closed-loop control of another direction on the same axis;
• and further thereby achieving the single instruction dual-direction synchronous loading.