3D Printing Transparent Sand Technology And Basic Mechanical Properties

Transparent soil deformation visualization model test technology is a new method mainly used to study the internal deformation and failure mode of soil,and it has received more and more attention and applied research in recent years.Although there are many studies on transparent sand,the technology still has defects,such as the excessive friction angle of fused silica sand,which distorts the physical and mechanical properties of the soil,the amorphous silicon micro powder is mainly spherical and lacks shape changes.Silica gel has poor physical and mechanical properties,the shape of broken glass is too sharp,and the shape characteristics of natural sand are quite different.To solve this problem,a 3D printing transparent sand particle technology based on contour rotation interpolation method to generate particle model is proposed,and physical and mechanical testing and numerical simulation research work are carried out.The main work of this article is as follows:(1)Based on the Fourier descriptor,the Fourier analysis of the two-dimensional contours of the particles was carried out,and the set of Fourier descriptors of the particles was obtained.(2)Based on the transparent sand preparation method,research and development of new transparent sand preparation materials was carried out.A low-viscosity pore fluid matching the RI of the photosensitive resin was found,which broadened the selection range of transparent sand solid particles.Demonstrates the feasibility of printing transparent sand particles with SLA 3D printer using photosensitive resin as printing material.(3)Physical and mechanical properties testing of 3D printed transparent sand was carried out.A one-dimensional compression test,a direct shear test,and a triaxial compression test were used to systematically check the physical and mechanical characteristics of 3D printed transparent sand particles.Subsequently,a simple model test of rigid flat plate penetration into transparent granular sand is performed.The obtained soil displacement using PIV technique are compared with classical shallow strain path method(SSPM)solution.The compared results indicate that the proposed 3D printed transparent granular sands have the ability to capture the soil deformation pattern although the accuracy is needed to be further improved.The proposed 3D printed transparent granular sand technique could more exactly simulate the natural sand.(4)Using PFC3 D numerical simulation software,numerical simulation tests were performed on particles with complex shapes.By simulating direct shear tests under different vertical pressures and triaxial compression tests under different confining pressures,the contact force chains and displacement fields of the samples were observed and obtained.The stress-strain curve of the sample is obtained and compared with the laboratory test results,which verifies the reliability of laboratory tests.