Automatic feature recognition and tool path strategies for enhancing accuracy in double sided incremental forming

Incremental sheet forming (ISF) has demonstrated significant potential to form complex three-dimensional parts without using component-specific tools and is suitable for economically fabricating low-volume functional sheet metal parts. Single-point incremental forming (SPIF) uses only one tool to form components and requires additional setup to form complex geometries. Double-sided incremental forming (DSIF), using two tools (one on either side of the sheet), can form features from top and bottom of sheet in single setup. While forming components with multiple features, the accuracy of component depends on the tool path strategy used for each feature and sequence in which features are formed. Methodologies are developed to recognise features from free-form components modeled using single and/or multiple surfaces. Recognised features are sliced using horizontal, inclined or offset strategies (developed during the present work) based on the geometrical characteristics of a given feature. Selection of best-forming sequence is automated based on the relation between features and process mechanics. Results presented in this paper show that complex free-form geometries can be formed with good accuracy using proposed methodologies. Maximum deviation between the measured and ideal profiles is less than 400 μm, while using right sequence and appropriate tool path strategy.

[1]  Jian Cao,et al.  A new methodology for multi-pass single point incremental forming with mixed toolpaths , 2011 .

[2]  Bert Lauwers,et al.  Tool path generation for single point incremental forming using intelligent sequencing and multi-step mesh morphing techniques , 2013 .

[3]  M. Muzzupappa,et al.  Influence of some relevant process parameters on the dimensional accuracy in incremental forming: a numerical and experimental investigation , 2004 .

[4]  Anirban Bhattacharya,et al.  Compensations for Tool Path to Enhance Accuracy During Double Sided Incremental Forming , 2015 .

[5]  Paulo A.F. Martins,et al.  Revisiting the fundamentals of single point incremental forming by means of membrane analysis , 2008 .

[6]  Bin Lu,et al.  Feature-based tool path generation approach for incremental sheet forming process , 2013 .

[7]  Y. Wang,et al.  Incremental sheet metal forming: Advances and challenges , 2008 .

[8]  Niels Bay,et al.  Multi Stage Strategies for Single Point Incremental Forming of a Cup , 2008 .

[9]  Joost R. Duflou,et al.  Force prediction for single point incremental forming deduced from experimental and FEM observations , 2010 .

[10]  Horst Meier,et al.  Impact of superimposed pressure on dieless incremental sheet metal forming with two moving tools , 2011 .

[11]  Jian Cao,et al.  Deformation mechanics in single-point and accumulative double-sided incremental forming , 2013 .

[12]  Zixuan Zhang,et al.  A Mixed Toolpath Strategy for Improved Geometric Accuracy and Higher Throughput in Double-Sided Incremental Forming , 2014 .

[13]  Dongkai Xu,et al.  An efficient method for thickness prediction in multi-pass incremental sheet forming , 2015 .

[14]  Bert Lauwers,et al.  Feature Based Approach for Increasing the Accuracy of the SPIF Process , 2007 .

[15]  Dongkai Xu,et al.  Accumulative-DSIF strategy for enhancing process capabilities in incremental forming , 2012 .

[16]  Eungki Lee,et al.  Contour offset approach to spiral toolpath generation with constant scallop height , 2003, Comput. Aided Des..

[17]  Rakesh Lingam,et al.  Tool path design for enhancement of accuracy in single-point incremental forming , 2014 .

[18]  Joost Duflou,et al.  Asymmetric single point incremental forming of sheet metal , 2005 .

[19]  Horst Meier,et al.  Increasing the part accuracy in dieless robot-based incremental sheet metal forming , 2009 .

[20]  Joost Duflou,et al.  Accuracy Improvement in Single Point Incremental Forming through Systematic Study of Feature Interactions , 2011 .

[21]  N. Venkata Reddy,et al.  Importance of Feature Sequencing in Incremental Forming , 2015 .

[22]  N. V. Reddy,et al.  NON-DISCRETIZED APPROACH TO VISIBILITY ANALYSIS FOR AUTOMATIC MOLD FEATURE RECOGNITION USING STEP PART MODEL , 2012 .

[23]  S. Timoshenko,et al.  THEORY OF PLATES AND SHELLS , 1959 .

[24]  Johan Verbert,et al.  Laser Assisted Incremental Forming: Formability and Accuracy Improvement , 2007 .

[25]  Anirban Bhattacharya,et al.  Formability and Surface Finish Studies in Single Point Incremental Forming , 2011 .

[26]  Paul A. Meehan,et al.  Efficient force prediction for incremental sheet forming and experimental validation , 2014 .

[27]  Gershon Elber,et al.  Curve Evaluation and Interrogation on Surfaces , 2001, Graph. Model..

[28]  Jian Cao,et al.  Improvement of Geometric Accuracy in Incremental Forming by Using a Squeezing Toolpath Strategy With Two Forming Tools , 2011 .

[29]  Bijan Mollaei Dariani,et al.  Analysis of incremental sheet metal forming using the upper-bound approach , 2012 .

[30]  Jian Cao,et al.  Automatic 3D Spiral Toolpath Generation for Single Point Incremental Forming , 2010 .

[31]  Joost R. Duflou,et al.  Improved SPIF performance through dynamic local heating , 2008 .