Related explanations of three closed-loop electronic universal testing machine

The three-closed-loop electronic universal testing machine not only has the characteristics of a conventional electronic universal testing machine with a wide speed range, a large test stroke and flexible configuration, but also has the advantages of force, displacement and deformation control of electro-hydraulic servo testing machine. Therefore, it is a universal testing machine with good performance.
However, since the machine stability during force control and deformation control is closely related to the rigidity of the host and the rigidity of the sample, and generally plastics use a smaller tonnage, the rigidity of the host is lower, and the rigidity of the sample itself is not too large. Therefore, there are few models of three-closed-loop electronic universal testing machines below 10KN, while models below 10KN are commonly used in plastics.
As mentioned earlier, the stability of the three closed-loop type models is related to the sample. If the sample is single, the test method is relatively single and can be used. Otherwise, the control parameters of the test machine (i.e., the conventional P, I, and D parameters) need to be adjusted at any time. This is almost difficult for non-automatic testers to imagine. Therefore, from a general perspective, in addition to specific requirements for the control method, it is not easy to choose to test plastic materials.