The graded material structure has broad application prospects in aerospace

medical implants

energyabsorbing structures

etc. for its excellent mechanical properties and energy absorption. A graded minimal surface porous structure design method is proposed by imitating the structure of bamboo with graded structure

and linearly graded Gyroid structures and topological density graded Gyroid structures were designed based on this method. The porous structures were manufactured by laser powder bed fusion technology

and the bending properties of the uniform structure and graded structure were analyzed by bending test and digital image correlation technology. The experimental results show that the bending elastic modulus of the Gyroid porous structure is a linear function of porosity

and the critical porosity of bending fracture is between 80% and 85%. The linear graded porous structure has the asymmetric bending behavior like bamboo

and it has the highest bending toughness and no bending fracture when the porosity is distributed in the form of 70%→90%

while it has the highest bending strength when the porosity is distributed in the form of 90%→70%

which is 36.08% higher than the bending strength of the uniform Gyroid structure with porosity of 80%. It is demonstrated that bending deformation and fracture mode can be adjusted by the graded distribution mode of porosity. A structure with lightweight and high bending strength can be obtained by the reasonably graded structure design.