History of engineering & technology PVDF patches SMART materials Structural Health Monitoring Technology: general issues Terfenol-D analytical model beam model bi-stable oscillator bifurcation bistable oscillator computational fluid dynamics damage detection damage sensitive feature direct-force generator efficiency efficiency measurement electromagnetic electromagnetic energy harvester electromagnetic transducer energy harvester energy harvesting equivalent model finite element method (FEM) frequency response analysis frequency-up conversion harmonic balance method hysteretic effect lead zirconate titanate (PZT) load resistance optimization