tailieunhanh - Encyclopedia of Smart Materials (Vols 1 and 2) - M. Schwartz (2002) WW Part 15

Tham khảo tài liệu 'encyclopedia of smart materials (vols 1 and 2) - m. schwartz (2002) ww part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Possibility of shaping PVDF sensors spatial filtering Electrostrictive materials Used as sensor and actuators Lower hysteresis and creep Example Lead-magnesium niobate PMN Magnetostrictive materials Example Terfenol-D compared to piezoelectric Potentially larger recoverable strain than piezoelectric Higher force and strain capability than piezoceramics typically 1000 microstrain deformation Suited for high-precision applications Suited for compressive load carrying components Very durable Shape-memory alloys SMA Example nitiNol Large recoverable strain 8 used largely for actuation due to large force generation Low voltage requirements Optical fibers Examples Bragg grating Fabry-Perot Suited for remote sensing of structures Corrosion resistant Immune to electric interference Small light and compatible with advanced composite Electrorheological fluids ER Example Alumino-silicate in paraffin oil Simple and quiet devices Suitable for vibration control Offers significant capability and flexibility for altering structural response Low density Magnetorheological fluids MR Simple and quiet devices Quick response time Suitable for vibration control Offers significant capability and flexibility for altering structural response Low voltage requirements Behavior not affected by impurities Suitable for wide range of temperatures Lower np àị ratio than ER Microphones Low cost Large dynamic range Excellent linearity Piezoelectric ceramics are brittle Cannot measure direct current Susceptible to high hysteresis and creep when strained in directi of poling . stack actuators More sensitive to temperature variations than piezoelectrics Low recoverable strain Only for compression components Nonlinear behavior Suited for low-frequency 0-10 Hz and low-precision application Slow response time Complex constitutive behavior with large hysteresis Used for sensing alone Behavior is complicated by therma Low-frequency applications Nonlinear behavior Cannot tolerate impurities Fluid .