Abstract: Pre-cure forming (or net shape forming) is an efficient manufacturing method for large composite structural components, especially suitable for aerospace and transportation industries. Pre-cure forming of composites, involving pressure shaping and precision contour cutting before curing, is a critical practical technique that delivers efficient shaping with minimal waste and is especially suited for the co-curing process. However, theoretical modeling of cutting processes for fiber/uncured-viscoelastic-resin composites remains limited as resin properties strongly depend on temperature and loading frequency. In this study, a three-term-Prony-series viscoelastic resin model incorporating the time-temperature superposition principle was proposed and applied in finite element modeling (FEM) of unidirectional carbon fiber-reinforced polymer prepreg laminates (CPL). The main contributions included: (1) development of a representative volume element (RVE) model for CPL that accounts for loading frequency and temperature effects, validated against dynamic tensile test data with an average error of approximately 12%; (2) establishment of a coupled heat generation and transfer model that accurately predicted the thermal distribution during cutting, achieving a prediction error within 7% for peak surface temperature; and (3) construction of a temperature- and frequency-dependent model for ultrasonic vibration cutting of CPL, yielding a feed force prediction error of 17%. By integrating frequency and temperature effects into the cutting mechanics framework, this study provides a robust methodology for elucidating the underlying mechanisms of ultrasonic cutting and offers an effective approach for modeling mechanical interactions in viscoelastic materials.

Keywords: FE modelling, ultrasonic vibration, cutting process, CFRP laminates, viscoelastic.

Biography: Dr. Feng Feng is an Associate Professor at Tsinghua Shenzhen International Graduate School and Deputy Director of the Institute of Intelligent Instruments and Equipment. His research focuses on intelligent manufacturing and precision machining. He has published over 100 academic papers, been granted more than 20 Chinese invention patents and PCT patents, and led over 20 research projects including NSFC programs and national major science and technology projects. He serves as a committee member of both the Surface Engineering Division of CMES and the Advanced Cutting Technology Division of China Cutting Tool Association.