Contact surface recognition method for the numerical simulation of shield tunneling

The numerical simulation of shield tunneling is a complex calculation process due to the continuous dynamic contact relationship. Setting the interaction between cutterhead and soil is the key for simulation. Because of the contact surface continuously updating with the cutting scrap separation, surface to surface contact algorithm should be used in spite of lots of restrictions are claimed in this algorithm. It is also very time-consuming to define the right contact surface manually. In order to make the contact surface defined simply and efficiently, the contact surface recognition program is designed by user subroutine. The program provides a function to calculate and select the normal of solid element surface which is a good complement of ABAQUS software. The surface recognition method can provide not only an effective means for the intelligent establishment of shield tunneling simulation system but also a reference for the study of automatic surface recognition in complex structure.