Force Prediction for Incremental Forming of Polymer Sheets.

Area of Science:

• Materials Science
• Manufacturing Engineering
• Mechanical Engineering

Background:

• Incremental Sheet Forming (ISF) is a cost-effective method for prototyping and small-batch production of 3D components.
• Accurate estimation of forming force in ISF is crucial for process setup, damage prevention, wear reduction, energy efficiency, and final part geometry.
• Existing methods for estimating forming forces are primarily developed for metal sheets, necessitating new approaches for polymer sheets.

Purpose of the Study:

• To develop and validate procedures for predicting the axial forming force during Single Point Incremental Forming (SPIF) of polymer sheets.
• To extend the applicability of ISF force prediction models to polymer materials.

Main Methods:

• Development of a numerical model using the Finite Element Method (FEM) incorporating a hyperelastic-plastic constitutive equation.
• Formulation of a semi-analytical model based on the specific energy concept adapted from machining principles.
• Experimental validation using polycarbonate (PC) and polyvinyl chloride (PVC) sheets to determine model parameters and verify predictions.

Main Results:

• Both the numerical and semi-analytical models provide accurate predictions of axial forming forces for polymer sheets.
• Experimental tests confirm good agreement between predicted and actual forming forces for PC and PVC.
• The numerical model demonstrates capability in accurately predicting temperature distribution and thickness reduction during the SPIF process.

Conclusions:

• The presented numerical and semi-analytical models are effective tools for predicting axial forces in the SPIF of polymer sheets.
• These models contribute to a better understanding and optimization of ISF processes for polymer materials.
• The validated models can aid in process design, material selection, and energy consumption analysis for polymer ISF applications.