Validation of Analytical Damping Ratio by Fatigue Stress Limit

[摘要] The optimisation process of a vibration energy harvester is usually restricted to experimental approaches due to the lack of an analytical equation to describe the damping of a system. This study derives an analytical equation, which describes the first mode damping ratio of a clamp-free cantilever beam under harmonic base excitation by combining the transverse equation of motion of the beam with the damping-stress equation. This equation, as opposed to other common damping determination methods, is independent of experimental inputs or finite element simulations and can be solved using a simple iterative convergence method. The derived equation was determined to be correct for cases when the maximum bending stress in the beam is below the fatigue limit stress of the beam. However, an increasing trend in the error between the experiment and the analytical results were observed at high stress levels. Hence, the fatigue limit stress was used as a parameter to define the validity of the analytical equation.

[发布机构] School of Engineering and Physical Sciences, Heriot-Watt University, No. 1, Jalan Venna P5/2, Precinct 5, 62200, Malaysia^1;Intel PSG, Bayan Lepas Technoplex, Medan Bayan Lepas, Penang; 11900, Malaysia^2;Center for Automotive Research and Electric Mobility (CAREM), Universiti Teknologi PETRONAS (UTP), Tronoh; 31750, Malaysia^3

[效力级别] 工业技术 [学科分类] 工业工程学

[关键词] Analytical equations;Analytical results;Determination methods;Equation of motion;Experimental approaches;Fatigue limit stress;Finite element simulations;Vibration energy harvesters