Two-Dimensional Finite Element Analysis and Cutting Force Model for the Cutting of Circular Steel Bars Using Negative...

Area of Science:

• Mechanical Engineering
• Materials Science
• Civil Engineering

Background:

• Cutting forces on steel bars are critical for shield tunneling, particularly when encountering pile foundations.
• Understanding initial cutting phase forces is essential for optimizing tunneling parameters.

Purpose of the Study:

• To develop a computational model for predicting cutting forces on steel bars during the initial orthogonal cutting phase.
• To investigate the influence of material properties, strain rate, and temperature on cutting forces.
• To analyze the impact of chip accumulation and slip line stress variations on force predictions.

Main Methods:

• Utilized 2D finite element analysis (FEA) to simulate orthogonal cutting with negative rake angle cutters.
• Combined slip line theory and shear band model for force calculation.
• Incorporated the Johnson-Cook material model to account for strain rate and temperature effects.
• Studied common construction steels: AISI 1040, AISI 4340, and AISI 304.

Main Results:

• Developed a model to calculate cutting forces for negative rake angle cutters on steel bars.
• Model predictions for horizontal cutting force showed an average error of 14.23% compared to FEA simulations.
• Vertical cutting force calculations exhibited higher errors, with an average of 14.06%.
• Chip accumulation was identified as a significant factor influencing horizontal cutting force.

Conclusions:

• The developed computational model provides valuable insights into cutting forces during the initial phase of steel bar cutting.
• Material properties, temperature, friction, and bar radius influence model accuracy.
• Further refinement is needed for vertical force prediction accuracy, but the model offers a basis for tunneling parameter optimization.