Seasonal dynamics of structure and diversity of insect communities in wheat fields 麥田昆蟲群落結(jié)構(gòu)及多樣性的季節(jié)動(dòng)態(tài)
Seasonal dynamics of structure and diversity of insect communities in the poplar nursery 楊樹苗圃昆蟲群落結(jié)構(gòu)及多樣性季節(jié)動(dòng)態(tài)
The paper derived the formulae for the strain response mode with the knowledge of dynamics of structures, of materiaj mechanics, of elastic mechanics, and pointed out their use range . a computer program is worked out with fortran power stations 4.0, it can compute the characteristic value, the characteristic vector and the strain mode for a bridge structure, and it is verified correct 論文綜合結(jié)構(gòu)動(dòng)力學(xué)、材料力學(xué)、彈性力學(xué)等知識(shí)推導(dǎo)出橋梁結(jié)構(gòu)應(yīng)變響應(yīng)模態(tài)模型的數(shù)學(xué)公式,指出了該方法的適用范圍,基于fortranpowerstation4.0計(jì)算機(jī)工作平臺(tái),用fortran語(yǔ)言編制了能h算橋梁結(jié)構(gòu)特征值及特征向帛羽小于變模態(tài)的哭小m序。
The research of approach to monitor bridge state has become a hot spot in the engineering through the theory of dynamic of structures and the test technology . structure mode parameters ( vibration frequency, mode of vibration ) are the functions of physical property parameters ( mass, rigidity, damping ) . the damage of structures leads to the transformation of physical property parameters, and certainly leads to the transformation of structure mode parameters finally 結(jié)構(gòu)模態(tài)參數(shù)(振動(dòng)頻率、振型)是結(jié)構(gòu)物理參數(shù)(質(zhì)量、剛度、阻尼)的函數(shù),而結(jié)構(gòu)損傷必然會(huì)導(dǎo)致結(jié)構(gòu)物理參數(shù)的變化,最終會(huì)引起結(jié)構(gòu)模態(tài)參數(shù)的變化,因此利用現(xiàn)代的信號(hào)測(cè)試技術(shù)測(cè)出結(jié)構(gòu)模態(tài)參數(shù)的變化就可以對(duì)橋梁的損傷程度、承載能力進(jìn)行判斷。
The research of approach to monitor bridge health state has become a hot spot which social and technologic people have explored through the theory of, dynamics of structures and the lest technology . structure mode parameters ( vibration frequency, mode of vibration and damping ) are the functions of physical property parameters ( mass, rigidity, damping ) . the damage of structures certainly leads to the transformation of physical property parameters 結(jié)構(gòu)模態(tài)參數(shù)(振動(dòng)頻率、振型和模態(tài)阻尼等)是結(jié)構(gòu)物理特性參數(shù)(質(zhì)量、剛度、阻尼)的函數(shù),結(jié)構(gòu)損傷必然導(dǎo)致結(jié)構(gòu)物理特性的變化,即結(jié)構(gòu)參數(shù)發(fā)生改變,利用現(xiàn)代的測(cè)試技術(shù)準(zhǔn)確地測(cè)出這些參數(shù)變化,就可對(duì)橋梁損傷狀況進(jìn)行評(píng)估,應(yīng)變模態(tài)方法識(shí)別橋梁損傷就是基于這種理論提出的,本文所做的主要工作為:1