噪声与振动控制
譟聲與振動控製
조성여진동공제
NOISE AND VIBRATION CONTROL
2015年
4期
101-106
,共6页
振动与波%结构损伤%模态柔度%模量灵敏度%损伤识别
振動與波%結構損傷%模態柔度%模量靈敏度%損傷識彆
진동여파%결구손상%모태유도%모량령민도%손상식별
vibration and wave%structure damage%modal flexibility%modulus sensitivity%damage detection
基于模型修正技术的结构损伤识别方法，无需事先知晓结构的损伤位置，比仪器直接探测更具优势。模型修正大多以模态频率和振型为修正目标。然而，结构损伤对系统的模态频率和振型影响较小，采用模态频率和振型为目标的传统修正方法，难以识别出结构的损伤。为此，引入对结构损伤极为灵敏的模态柔度矩阵，研究以模态柔度矩阵为目标函数的损伤识别方法。选取某带孔的矩形长铁片为研究对象，沿其纵向等分为31块，计算模态柔度矩阵关于各等效模量相对量的灵敏度。结合灵敏度矩阵，利用实测和有限元模型间的柔度矩阵残差建立目标函数，并引入正则化方法求解目标函数的超定方程组。经过9次迭代目标函数收敛，损伤识别结果与实际值保持高度一致，从而验证该方法的正确性和实用性。
基于模型脩正技術的結構損傷識彆方法，無需事先知曉結構的損傷位置，比儀器直接探測更具優勢。模型脩正大多以模態頻率和振型為脩正目標。然而，結構損傷對繫統的模態頻率和振型影響較小，採用模態頻率和振型為目標的傳統脩正方法，難以識彆齣結構的損傷。為此，引入對結構損傷極為靈敏的模態柔度矩陣，研究以模態柔度矩陣為目標函數的損傷識彆方法。選取某帶孔的矩形長鐵片為研究對象，沿其縱嚮等分為31塊，計算模態柔度矩陣關于各等效模量相對量的靈敏度。結閤靈敏度矩陣，利用實測和有限元模型間的柔度矩陣殘差建立目標函數，併引入正則化方法求解目標函數的超定方程組。經過9次迭代目標函數收斂，損傷識彆結果與實際值保持高度一緻，從而驗證該方法的正確性和實用性。
기우모형수정기술적결구손상식별방법，무수사선지효결구적손상위치，비의기직접탐측경구우세。모형수정대다이모태빈솔화진형위수정목표。연이，결구손상대계통적모태빈솔화진형영향교소，채용모태빈솔화진형위목표적전통수정방법，난이식별출결구적손상。위차，인입대결구손상겁위령민적모태유도구진，연구이모태유도구진위목표함수적손상식별방법。선취모대공적구형장철편위연구대상，연기종향등분위31괴，계산모태유도구진관우각등효모량상대량적령민도。결합령민도구진，이용실측화유한원모형간적유도구진잔차건립목표함수，병인입정칙화방법구해목표함수적초정방정조。경과9차질대목표함수수렴，손상식별결과여실제치보지고도일치，종이험증해방법적정학성화실용성。
The damage detection method based on model updating is more convenient and advanced than the traditional instrument detection techniques. In this method, it is not necessary to known the damage locations of structures. The model updating methods are usually based on the targets of mode frequencies and shapes updating. However, the structure damage has little effect on the mode frequencies and shapes. So, the damage can hardly be detected with traditional updating methods which take the mode frequencies and shapes as objectives. In this paper, the mode flexibility matrix, which is very sensitive to the structure damages, was introduced. The structure damage detection method with the flexibility matrix as the objective was studied. A rectangular iron panel with holes was selected as the object of study. It was divided into 31 pieces in longitudinal direction. The mode flexibility matrix sensitivity to each equivalent modulus was calculated. The objective function was established with sensitivity matrix and mode flexibility residual. Then, the ill posed equations of objective functions were solved by regularization method. The objective function converged with nine iterations and the result of damage identification was in very good agreement with the real value. It is verified that the method is accurate and practical.
