Optimization of a flexible piezoelectric module structure based on a lead-free piezoceramic embedded in nanofiber composites

•The flexible module structures based on piezoceramic nanofibers were optimized.•Energy harvesting single modules were optimized according to electrode structure.•Dual modules were optimized electrode structure according to arrayed x- and z-axis, and connected in series or in parallel.•The energy harvesting properties and the structural health monitoring sensing capabilities were analyzed.