Dynamic Characteristic Analysis Of Flexible Arc Arch Based On Absolute Node Coordinate Formulation

As an important structural form,the arch is concerned by most engineering designers because of its unique shape and good mechanical propertices.Such structures are widely used in civil engineering,machinery manufacturing,aerospace and other fields.Therefore,the dynamic characteristics of flexible circular arc arch under concentrated load and uniform load are studied by absolute node coordinate formulation(ANCF).The main works are included as follows:(1)Based on the ANCF,the dynamic equation of the flexible curved beam is established.The displacement field,absolute position vector and node coordinate array of any point on the flexible curved beam element under absolute coordinate system are described,the mass matrix of curved beam element,nonlinear stiffness matrix,and generalized external force array are deduced,and the dynamic equation of flexible curved beam element is establisihed.(2)The calculation efficiency of absolute node coordinate method is improved.By separating the nonlinear stiffness array from the nonlinear generalized elastic force array and making the corresponding derivation and simplifying the Jacobian matrix,the method of calculating the efficiency of ANCF in the dynamic equation of flexible circular arc arch can be improved quickly.On this basis,combined with the dynamic analysis of curved beam pendulum,the method of combining iteration is used to calculate,and the correctness of the single pendulum model of curved beam under large rotation and large deformation is verified.(3)The dynamic characteristics of flexible arc arch are analyzed based on absolute node coordinate method.For the modal characteristics of the flexible arc arch,the above kinetic equations are calculated by MATLAB programmintg and compared with the calculation results of NX.The results show that the error of the simulation results of the two methods is small,which indic:ates the validity of the established mathematical model.Then,the dynamic response of the flexible arc arch under the action of concenlrated load and radial uniform load is studied under the constraint conditions of varnous arch feet.The results show that,from the angle of external load,the uniform load has little effect on the dynamic stability of the flexible arc arch,and from the point of view of arch foot constraint,the fixed constraint of the arch foot is relatively stable.