Research On The Quasi-static Compressive Properties Of Composite Corrugated Panels

Corrugated panel is a material structure with dual properties of structure and function.It has lower relative density,higher specific bending stiffness and excellent specific energy absorption performance.Therefore,it has been widely used in aerospace,marine,construction,military,automotive industries and other fields.In order to improve the performance of corrugated panels,corrugated panels of various configurations are combined to obtain composite materials with excellent properties.In this thesis,the effects of configuration,cell span and cell wall thickness on the quasi-static compressive performance of composite corrugated panels are studied by means of experiment and finite element analysis,which is of great significance for the design and application of corrugated panels.This thesis takes single-layer corrugated panels,double-layer composite corrugated panels with single core and double-layer composite corrugated panels with different cores as the research objects.Single-layer corrugated panels include four types:triangle,rectangle,trapezoid and sinusoidal types.Double-layer composite corrugated panels with single core include seven types such as triangle overlapping,triangle symmetry and trapezoidal overlapping types.Double-layer composite corrugated panels with different cores include twelve types such as triangle-rectangle,triangle-trapezoid and triangle-sinusoidal types.First,the quasi-static compressive and tensile tests of corrugated paperboards and their base paper sheets were carried out respectively,and the relevant properties of the base paper sheets were obtained from the tensile test.Secondly,with the help of ANSYS/LS-DYNA,the quasi-static compressive finite element models of single-layer corrugated panels,double-layer composite corrugated panels with single core and double-layer composite corrugated panels with different cores were established.For single-layer corrugated panels,the finite element simulative results are compared with the tested results,and they are in good agreement,which ensures the reliability of the finite element models.Finally,the stress-strain curves obtained by the finite element analysis and the experiments were integrated to obtain the energy absorption curves,and then the curves were divided by the stress to obtain the energy absorption efficiency curves.The initial peak stress,densification strain,platform stress,effective energy absorption per unit volume and specific energy absorption were obtained from these curves.The quasi-static compressive performance of composite corrugated panels was evaluated combined with the simulative deformation modes and stress-strain curves.Based on the reliable finite element models,the quasi-static compressive performance of composite corrugated panels with different configurations and structural parameters(element span and cell wall thickness)were studied by parametric methods.The obtained deformation modes,stress-strain curves and related energy absorption performance evaluation indexes were presented in the forms of tables and charts.After discussions,the following conclusions were drawn:1)The stress-strain curves of corrugated panels include four stages:linear elasticity,yield,platform and densification.The configuration has a great influence on the compressive performance of corrugated panels.When the cell span and cell wall thickness are constant,for single-layer corrugated panels,the initial peak stress and densification strain of trapezoidal corrugated panel are the maximum,the platform stress of sinusoidal corrugated panel is the maximum,while the effective energy absorption and specific energy absorption per unit volume of rectangular corrugated panel are the minimum.For double-layer composite corrugated panels with single core,the initial peak stress and platform stress of sinusoidal symmetric corrugated panels are the largest,the effective energy absorption per unit volume of rectangular double-layer corrugated panels is the smallest,and the specific energy absorption of triangle overlapping corrugated panels is the smallest.For double-layer composite corrugated panels with different cores,the platform stress of rectangular-trapezoidal corrugated panel is the largest,the initial peak stress of triangular-rectangular corrugated panel is the largest;however the effective energy absorption per unit volume of this corrugated panel is the smallest,the specific energy absorption of trapezoidal-triangular corrugated panel is the smallest.2)For three types of corrugated panels with a given configuration,when the cell wall thickness is constant,with the increasing of cell span,the initial peak stress,platform,stress,effective energy absorption per unit volume and energy absorption of corrugated panels are decreasing,but the values of above indicators are increasing first and then decreasing for the sinusoidal overlapping corrugated panels.And the values of performance indicators rely on the cell spans by the laws of quadratic functions.When the cell span is constant,the values of indicators of three types of corrugated panels increase with the increase of cell wall thickness,and have quadratic functional relations with the cell wall thicknesses.