13th International Conference on the Technology of Plasticity (ICTP 2021): Taylan Altan Honorary Symposium
Program Organizers: Glenn Daehn, Ohio State University; Libby Culley, The Ohio State University; Anupam Vivek, Ohio State University; Jian Cao, Northwestern University; Brad Kinsey, University of New Hampshire; Erman Tekkaya, TU Dortmund; Yoshinori Yoshida, Gifu University
Monday 9:15 AM
July 26, 2021
Room: Virtual: Room A
Location: Virtual
Session Chair: Gracious Ngaile, North Carolina State University
Enhancing Tool Life by Manipulating the Punch & Die Elastic Strain Field during Forging: Gracious Ngaile1; 1North Carolina State University
Tool life is a major factor in the cost of forgings, productivity, and part integrity. This paper will discuss a new methodology for enhancing the tool life of forging dies by manipulating the elastic strain field induced in the die and punches during forging, such that the retained contact stresses at the tool-workpiece interface are minimized or eliminated during punch ejection and release of the forging from the dies. The retained contact stress is attributed to the spring-back of the dies/punches. Finite element simulations of the proposed tooling architectures which facilitate the relaxation of elastic strain field in the die at the end of the forging stoke will be presented. To assess the viability of this technique, a number of forging geometries have been simulated including, CV joint, pinion shaft, hub spindle, and gearbox main shaft. The researchers are currently developing a laboratory scale tooling setup for experimental validation.
Investigation of Effects of Part Features in Single Point Incremental Forming of Narrow Channels: Suwat Jirathearanat1; Dharmesh Kumar1; Kai Soon Fong1; Atsushi Danno1; A Senthil Kumar2; 1Singapore Institute of Manufacturing Technology; 2National University of Singapore
Narrow channels or ribs can be commonly found in sheet metal products. These narrow with high length-to-width aspect ratio channels are often integrated into sheet metal panels for functional features such as stiffeners or guide rails of various topographies, i.e. straight line or composite of curves. This work focused on development of Single Point Incremental Forming (SPIF) as a cost-efficient forming alternative to stamping or embossing of these features in short-series production. These channels present unique forming challenges, i.e. effects of channel spline geometry, varying cross section, end geometries on part formability and geometrical accuracy. SPIF of SS316L 0.5mm-thick narrow channels of three different geometries with maximum width of 20mm and its length-to-width aspect ratio lager than 5, i.e. 1) straight channel, 2) taper channel, and 3) curvature channel, was investigated. Based on the experimental results, 5mm dia. carbide tool and 0.1mm step-down size was recommended to optimize SPIF of these narrow channels. The effects of the different part features and their interactions with SPIF forming parameters on part formability and deviations are presented and analyzed for further development of die-less narrow channel forming for sheet metal industry.
Self-optimized, Intelligent Open Loop Controlled Steel Strip Straightening Machine for Advanced Formability: Fabian Bader1; Eugen Djakow1; Lukas Bathelt2; Werner Homberg1; Christian Henke2; Ansgar Trächtler2; 1Paderborn University; 2IEM-Fraunhofer
Innovative self-correcting process control techniques which adapt to the initial geometric characteristics of the strip are a promising approach to fix the local varying distortion of coiled strips by optimizing the leveling process. This paper presents an innovative strategy to improve straightening of ahss materials (1.4310). This implies optimized leveling, adding minimal plastic deformation and, thus, strain hardening. Therefore, an “intelligent straightening machine” was developed which will be presented. To operate an intelligent straightening machine a reliable online measurement of the surface defects is fundamentally essential. This paper describes an approach towards the measurement of a bent steel strip for an automatic straightening process. Therefore, various ways of measuring the bending curvature are investigated. Optical, tactile and the MagnaTest are compared with each other. The bending measurement is linked to open/closed loop control and therefore providing an optimal straightening result in regards of formability, leveling and reduced strain hardening.
Finite Element Analysis of Die Quenching 22MnB5 Steel Sheets: Haydar Livatyali1; 1Yıldız Technical University
Mathematical modeling of heat treatment processes necessitates dealing with inherent complexities such as large material property variations, phase transformations, complex inter-parameter couplings and boundary conditions. A mathematical framework based on a finite element model capable of predicting temperature history and thus, evolution of phases during heat treatment of the boron steel 22MnB5 through the inverse use of CCT diagram was developed. This novel model named the “gridding model” was integrated into the commercial FEA software MSC.Marc® by the user subroutine PlotV. Accuracy of the model was verified by simulating some die quenching experiments in the literature as well as those that were conducted in the laboratory. Simulation results show that if thermo-mechanical-metallurgical couplings are modeled correctly, the novel model can predict the temperature history and evolution of phases with an acceptable accuracy.
A Vision of Numerically Controlled, Autonomous Manufacturing and Metal Forming: Glenn Daehn1; 1The Ohio State University
Here I lay out a vision for Hybrid Autonomous Manufacturing. Imagine you have a robot-automaton machinist who really likes and knows deformation. What would this enable? What’s needed to get there? Use cases and brief research agenda are presented.