Simulation Analysis Of Multilayer Piezoelectric Stack Actuator Based On Finate Element Method

Piezoelectric injector is the key part of diesel engine high pressure common rail system, Its execution component is the piezoelectric stack actuator. Compared with the traditional electromagnetic valve type of actuator, it has the advantage of fast response, large driving force, and high precision. As energy conservation and emissions reduction requirements and increasingly strict emission regulations, the requirements for the fuel injection pressure and injection frequency are also more and more high; the advantages of piezoelectric stack actuators are more obvious. It develops rapidly in recent years, with good development trend. Its output characteristics and modal and fatigue characteristics has a very important influence for the work performance piezoelectric injector. Therefore, the research of piezoelectric stack actuator has the very vital significance.At present, Oil pressure efi technology is mastered and applied by some auto industry more developed countries of the world. It belongs to the more advanced technology. Worldwide, especially in China, the practical application of piezoelectric stack actuator has not been a wide range of promotion. So far the domestic aspects of the research are less in our country. In order to form better understanding and application of piezoelectric stack actuator and a relatively comprehensive and systematic understanding performance of all aspects of piezoelectric stack actuator, this paper has carried on the preliminary analysis and discussion for the static characteristics and pre-stressed modal, as well as fatigue life, fatigue damage and so on various aspects performance on the basis of the finite element analysis.At first, using the ANSYS parametric design language APDL to establish the finite element model of the piezoelectric stack actuator. After carried on the static analysis, the static displacement output characteristics and force output characteristic of the piezoelectric stack actuator were gotten. The data were compared with the experiment, and the accuracy of the finite element model was validated. After that the modal analysis and pre-stressed modal analysis was carried out on the piezoelectric stack actuator under the natural state and the actual working status. The natural frequency and vibration of piezoelectric stack actuator type figure were gotten. And the comparison analysis of the two kinds of analysis data was carried on. After comparison, we could find that the vibration frequency under the action of prestress is greater than vibration frequency with no under the action of prestress. Its natural frequency loaded pre-tightening force is higher, and its dynamic characteristics are good. Finally on the basis of static analysis, the S-N fatigue analysis of the piezoelectric stack actuator was carried on by using fatigue analysis software ANSYS n Code Design Life. The S-N Fatigue analysis was carried out on the piezoelectric stack actuator. The cloud fatigue of fatigue life and fatigue damage analysis data and so on were gotten. The stress and strain in working state and dangerous place were found. The fatigue life of dangerous location under actual working state was obtained, providing a basis for structure optimization design of piezoelectric stack actuator.