iv
Sheet metal forming technologies are challenged especially by the improvements in
the automotive industry in the last decades. To fulfill the customer expectations,
safety requirements and market competitions, new production technologies have
been implemented. This study focuses on the assessment of conventional and new
sheet metal forming technologies by performing a systematic analysis. A geometry
spectrum consisting of six different circular, elliptic, quad cross-sections are
selected for the assessment of conventional deep drawing, hydro-mechanical deep
drawing and high-pressure sheet metal forming. Within each cross-section, three
different equivalent drawing ratios are used as a variant. More than 200 numerical
experiments are performed to predict the forming limits of three competing
processes. St14 stainless steel is used as the material throughout the assessment
study. The deformation behavior is described by an elasto-plastic material model
and all numerical simulations are carried out by using dynamic-explicit commercial
The process validation is done by interpreting the strain results of numerical
experiment. Therefore, the reliability of predictions in the assessment study highly
depends on the quality of simulations. The precision of numerical experiments are
verified by comparing to NUMISHEET benchmarks, analytical formulation, and
experiments to increase the assets of the assessment study.
The analyses revealed that depending on the workpiece geometry and dimensional
properties certain processes are more preferable for obtaining satisfactory products.
The process limits for each process are established based on the analyzed crosssections
of the spectrum. This data is expected to be useful for predicting the
formability limits and for selecting the appropriate production process according to
a given workpiece geometry.Dynamic-explicit FEM, Deep drawing, Hydroforming, Forming limits,
Process evaluation
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12606159/index.pdf |
| Date | 01 June 2005 |
| Creators | Onder, Erkan Ismail |
| Contributors | Tekkaya, Erman A. |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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