ميلاد تهراني فر

Quasi-Zero Stiffness (QZS) torsional vibration isolators are one of the most effective tools for reducing unwanted vibrations in mechanical systems, especially at low frequencies. This thesis investigates the dynamic modeling and performance of QZS isolators. The main objective of the research is to mathematically model and analyze the dynamic behavior of the system under different loading conditions and external excitations in order to eva‎luate and optimize the isolator performance in reducing two-dimensional torque fluctuations in both linear and nonlinear behavior modes. Traditional linear isolators have limitations in dynamic environments and often lead to amplification and failure. In contrast, QZS isolators exhibit near-zero stiffness in equilibrium, which allows them to absorb significant torsional changes without resistance. This research addresses the equations governing the dynamic behavior of these isolators and emphasizes the effects of hardening and softening stiffness. By balancing these stiffness characteristics, we demonstrate improved energy absorption and resistance under operating conditions. The analysis results showed that the spring stiffness parameter has the greatest impact on the system response and small changes in this parameter can lead to significant changes in the response amplitude. Also, comparing the performance of the QZS isolator with linear isolators showed that the QZS performs better at low frequencies. This research presents the results of numerical simulations and sensitivity analyses. Finally, suggestions are made for improving the design and using new materials and advanced optimization methods to increase the efficiency of these systems under different operating conditions.

جداساز ارتعاش گشتاور، سختي شبه صفر (QZS) , سختي شبه صفر (QZS) , مدل‌سازي ديناميكي , تحليل حساسيت , فركانس طبيعي

torque vibration isolator , quasi-zero stiffness (QZS) , dynamic modeling , sensitivity analysis

miladtehranifar

majidrajabi