本文選題：隨機(jī)缺陷 + 網(wǎng)架結(jié)構(gòu)　； 參考：《河北科技大學(xué)》2014年碩士論文

【摘要】：大跨度空間網(wǎng)架結(jié)構(gòu)由于其重量輕、結(jié)構(gòu)合理、造型優(yōu)美和力學(xué)性能好等優(yōu)點(diǎn),被廣泛應(yīng)用于大跨度公共建筑和民用設(shè)施。由于實(shí)際結(jié)構(gòu)承受的荷載隨機(jī)性較強(qiáng)且材料特性等具有各種初始隨機(jī)缺陷,結(jié)構(gòu)的幾何特性、損傷演變機(jī)制和承載能力與設(shè)計的理想化模型往往會有所差異,因此原因發(fā)生損傷或者破壞的潛在危險較大,所以網(wǎng)架結(jié)構(gòu)的隨機(jī)損傷研究日益受到重視。另一方面,隨著使用時間的增長,結(jié)構(gòu)由于超載、周圍環(huán)境變化、損傷累積等因素,損傷出現(xiàn)不可避免。并且結(jié)構(gòu)的初始隨機(jī)損傷也將會對結(jié)構(gòu)損傷的檢測帶來影響。本文針對這些問題,從以下幾個方面對有隨機(jī)缺陷的網(wǎng)架結(jié)構(gòu)損傷檢測問題進(jìn)行了研究:1)針對網(wǎng)架結(jié)構(gòu)的模態(tài)特性和小波變換在信號處理方面的優(yōu)勢,采用基于曲率模態(tài)差和小波變換相結(jié)合的損傷識別方法對網(wǎng)架結(jié)構(gòu)桿單元損傷進(jìn)行檢測,并通過對四種常見的網(wǎng)架結(jié)構(gòu)(正放四角錐網(wǎng)架、兩向正交正放網(wǎng)架、三向網(wǎng)架、蜂窩三角錐網(wǎng)架)進(jìn)行數(shù)值模擬,驗證了基于曲率模態(tài)差和小波變換相結(jié)合的損傷識別方法可以對多種網(wǎng)架進(jìn)行桿單元損傷識別。2)假定結(jié)構(gòu)隨機(jī)缺陷的統(tǒng)計特征服從正態(tài)分布,采用ANSYS的PDS技術(shù)并結(jié)合結(jié)構(gòu)模態(tài)分析確定結(jié)構(gòu)響應(yīng)的敏感參數(shù)。以四種常見網(wǎng)架結(jié)構(gòu)為例,用MATLAB編程生成符合正態(tài)分布的隨機(jī)數(shù),寫入ANSYS中構(gòu)造具有隨機(jī)缺陷的網(wǎng)架結(jié)構(gòu)模型。3)以具有隨機(jī)缺陷的網(wǎng)架結(jié)構(gòu)模型作為初始結(jié)構(gòu),進(jìn)行考慮缺陷的網(wǎng)架結(jié)構(gòu)損傷識別。識別仍采用基于曲率模態(tài)差和小波變換相結(jié)合的方法,將隨機(jī)模型與理想模型結(jié)果對比,表明在一定變異系數(shù)范圍內(nèi),該方法可用于有隨機(jī)缺陷網(wǎng)架結(jié)構(gòu)損傷識別。
[Abstract]:Long-span space truss structures are widely used in public buildings and civil facilities due to their advantages such as light weight, reasonable structure, beautiful shape and good mechanical properties.Due to the randomness of the load and the material characteristics of the actual structure with various initial random defects, the geometric characteristics, damage evolution mechanism and load-carrying capacity of the structure are often different from the idealized model of the design.Therefore, there is a great potential danger of damage or damage, so the random damage of truss structure is paid more and more attention.On the other hand, with the increase of service time, structural damage is inevitable due to overload, environmental changes, damage accumulation and so on.And the initial random damage of the structure will also have an impact on the detection of structural damage.Aiming at these problems, the damage detection problem of space truss structures with random defects is studied in this paper from the following aspects: (1) aiming at the modal characteristics of grid structures and the advantages of wavelet transform in signal processing,The damage detection method based on curvature modal difference and wavelet transform is used to detect the damage of truss elements.The numerical simulation results show that the damage identification method based on curvature modal difference and wavelet transform can be used to identify the damage of various grid elements. 2) assuming that the statistical characteristics of the random defects of the structure follow the normal distribution.The sensitive parameters of structural response are determined by ANSYS PDS technique and structural modal analysis.Taking four kinds of common grid structure as an example, the random number that accords with normal distribution is generated by MATLAB programming, and the grid structure model with random defect is constructed in ANSYS. 3) the grid structure model with random defect is taken as the initial structure.Damage identification of grid structure considering defects is carried out.The method based on curvature modal difference and wavelet transform is still used to identify the damage of space truss structures with random defects. The results of random model and ideal model are compared. The results show that the method can be used to identify the damage of space truss structures with random defects in a certain range of coefficients of variation.
【學(xué)位授予單位】：河北科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU317;TU356

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 葛騰飛;考慮隨機(jī)缺陷的網(wǎng)殼結(jié)構(gòu)損傷識別理論及試驗研究[D];北京工業(yè)大學(xué);2013年

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本文編號：1765708