在土木工程領域中, 智能結構系統(tǒng)越來越受到人們的重視, 而在智能結構系統(tǒng)中機敏材料是不可缺的元素, 它是構成智能結構中的傳感器和驅動器的關鍵材料。針對目前土木工程領域智能結構中存在的結構材料與機敏材料相容性差問題, 采用水泥基材料作為壓電機敏復合材料的基體, 通過調節(jié)水泥基材料組分和比例, 克服水泥基材料與壓電陶瓷在密度上的懸殊差異為材料準備帶來的困難, 制備出222 型水泥基壓電機敏復合材料。同時,采用集成了微型計算機、M TS 自動伺服試驗機、示波器、信號發(fā)生器、線性放大器和HP2IB 界面的測試系統(tǒng)測量222 型水泥基壓電復合材料的彈性性能、傳感性能和驅動性能。實驗結果表明, 在實驗范圍里, 該材料具有線彈性性能; 傳感性能和驅動性能具有明顯的頻率依賴性; 在超低頻范圍內, 222 型水泥基壓電復合材料的壓電電壓系數(shù)的模值隨頻率線性增大, 相角隨頻率增大開始時增大較快, 隨后趨于一常數(shù); 222 型水泥基壓電復合材料的壓電性能與聚合物基壓電復合材料相似。
關鍵詞: 機敏材料; 壓電性; 水泥基復合材料; 土木工程結構; 智能結構
Abstract: Intelligent structures are attracting more attention of scientists and engineers in the field of civil engi2 neering. In an intelligent structure, smart materials p lay animportant role, from w h ich sensors and actuators aremade. In order to solve them ismatch p roblem betw een smartmaterials and hostmaterials,w h ich is popular in the app lication of intelligent structures in the civil engineering field. Cement based materialsw ere chosen to be thematrix of p iezoelec2 tric smart materials. Th rough adjusting them ix p roportion and selecting the components of cement basedmatrix, p rob2 lem s of fabrication of 222 cement based p iezoelectric compositew ere overcome. U sing a testing system integrating com2
puter,M TS tester, oscilloscope, signal generator, linear amp lifier, HP2IB interface hardw are and softw are, the elastic, sensory and actuating p ropertiesw ere studied. The follow ing results can be obtained. The composite is linearly elastic. The sensory and actuating p roperties have obvious dependence on frequency. In the range of ultra low frequency, the
magnitude of p iezoelectric voltage factor of the composite increases linearly w ith frequency, the phase increases quick ly at first, but then app roaches to a constant, The p iezoelectric p roperties of the composite are sim ilar to those of polymer? ceram ic p iezoelectric composites.
Key words: smart materials; p iezoelectricity; cement based composites; civil engineering structures; intelligent structures