The early studies are mostly focused on the method of gluing piezoceramics on structural surfaces , which has some disadvantages such as difficulties to protect the ceramics and the connection wires , bad coupling with only one surface glued on the base materials , low signal - to - noise ratio etc . these problems can be solved using the embedded piezoceramics , and furthermore , the piezoceramics can be placed in the optimal positions , especially in the optimal deepness for the piezo - actuators , according to an optimization algorithm befor e they are embedded , so the actuator effects and sensor signals are thereby enhanced 早期的研究主要集中在表面粘貼壓電片的結(jié)構(gòu),表面粘貼壓電片具有一些無法克服的缺點。本文著重進(jìn)行利用埋入復(fù)合材料結(jié)構(gòu)的壓電傳感器和壓電驅(qū)動器對其振動進(jìn)行主動控制的相關(guān)理論和實驗研究,并介紹其相應(yīng)結(jié)果。埋入型壓電材料的優(yōu)點主要是能保護(hù)壓電傳感器和作動器及其連線、增強壓電材料和基體材料的耦合、優(yōu)化埋入壓電陶瓷的深度和厚度可增強壓電傳感器的測量信號并提高信噪比等。
The carbon fibers with low strength are broken easily according to thermal tension and bend stress damage models , and the carbon fibers with high modulus are broken easily according to thermal shear stress damage model in spite of less damage caused by heat . the carbon fibers with surface glue of epoxy resin are damaged easily in physical and chemical ways because of high oxygen extent and rigidity of epoxy resin 低強度碳纖維容易在熱應(yīng)力拉伸或彎折破壞模式下?lián)p傷;高模量碳纖維高溫?fù)p傷小,但國防科學(xué)技術(shù)大學(xué)研究生院學(xué)位論文容易以熱應(yīng)力剪切破壞模式下斷裂;環(huán)氧樹脂表面膠剛性較大,氧含量較高,使碳纖維容易受到化學(xué)損傷和熱應(yīng)力彎折損傷,均不宜用來制備c燈sic復(fù)合材料。