弹性薄板的损伤检测

Damage diagnosis for elastic thin plates

弹性薄板在工程中被广泛应用,板结构在各种因素作用下,引起结构的局部损伤,并最终导致板结构的破坏,因此,对弹性薄板进行在役无损检测,具有重要意义.目前,损伤检测研究大多还停滞在一维的梁结构中,对于二维的平面薄板结构的损伤检测,依然是一个研究难点,许多学者对板类结构的损伤检测,做出了有益的探索.在前人的研究基础上,提出用模态曲率差法对板结构进行损伤检测,为证明方法的有效性,采用一个四边简支混凝土薄板给予验证,算例表明,本文所提出的方法,对板的损伤位置能精确定位,并可根据模态曲率差的峰值大小,对损伤程度作出定性的判定.

Owing to damage happened in plate structure, the elastic modulus of material will be lowered in the damage area. According to the principle of mechanics, we can draw a conclusion that the deformation must be changed abruptly in the field of damage because which is inverse ratio of elastic modulus. Then using difference curvature detect damage will become possible. A plate simPlY supported along its four edges is adopted to analyze with numerical simulation by means of ANSYS; and the damage visualization program of modal curvature difference is edited. The results show that the method is effective in diagnosing damage location; additionally according to peak value of modal curvature difference, degree of damage is also judged qualitatively.