Finite element-based simulations have been performed on piezoelectric-based functionally graded materials (FGM). PZT (Lead zirconate titanate) and PVDF (Polyvinylidene fluoride) FGM composites have been investigated. Anomalous enhancement in output voltage has been observed at grading index n = 0.05 (Voltage = 210 V), which is 105 and 185% higher than the original material at n = 0 (PVDF) and n = a (PZT), respectively. Further, role of Young's modulus, dielectric constant, and piezoelectric constant was systematically investigated to understand this enhancement. It is found that performance of FGM not only relies on piezoelectric constants but also largely depends upon values of Young's modulus and dielectric constant.