As a plane plate structure to cover the hull or separate it into layers,trapezoidal structure plays an important role in ensuring the strength and unsinkability of the hull. Uneven stress of trapezoidal structure will produce huge pulling force,which is easy to cause deformation and fatigue stress concentration of trapezoidal structure. Based on this,an inversion method of displacement and strain field of ship trapezoidal structure based on inverse finite element method(iFEM)and fiber strain sensing is proposed,and the corresponding layout of fiber Bragg grating(FBG)sensors is given. By using Ansys finite element analysis method,the verification of relevant inversion methods based on simulation research is carried out. On this basis,the displacement and strain distribution monitoring and inversion experimental system of trapezoidal structure based on optical fiber sensor is constructed. The research show that the root mean square error(RMSE)of displacement reconstruction for double end fixed support trapezoidal structure is 0. 076,and the average relative error of strain field reconstruction is 6. 59％. The proposed method breaks through the difficult problem that the iFEM can not directly solve the structural strain field due to the low order of the shape function,and can provide technical support for the health monitoring of the ship trapezoidal structure and the improvement of the position and attitude precision of the shipborne weapon base.
关键词
逆有限元法/梯形结构/光纤Bragg光栅传感器/位移/应变场反演
Key words
inverse finite element method (iFEM )/trapezoidal structure/fiber Bragg grating (FBG )sensor/displancement/strain field inversion
维普
万方数据