Latest Developments in Sheet Metal Forming Technologies and Materials for Automotive Application: the Use of Ultra High Strength Steels at Fiat to Reach Weight Reduction at Sustainable Costs

Author(s):  
Manuel Lai ◽  
R Brun
2021 ◽  
Author(s):  
Zhihui Gong ◽  
Mandeep Singh ◽  
Bohao Fang ◽  
Dongbin Wei

Abstract Springback compensation is critical in sheet metal forming. Advanced techniques have been adopted in the design stage of various sheet metal forming processes, e.g. stamping, some of which are for complex shaped products. However, the currently available numerical approaches are not always sufficiently accurate and reliable. To improve the accuracy of springback compensation, an enhanced hybrid springback compensation method named Springback Path – Displacement Adjustment (SP-DA) method has been developed in this study based on the well-known conventional displacement adjustment (DA) method. Its effectiveness is demonstrated using FEM analysis of low, medium and high strength steels adopted in automobile industry, in which a symmetrical model owning geometry complexity similar to an auto body panel was established. The results show this new enhanced SP-DA method is able to significantly improve the accuracy of springback compensation comparing to conventional displacement adjustment technique.


2013 ◽  
Vol 581 ◽  
pp. 137-142 ◽  
Author(s):  
Miklós Tisza

In this paper, some recent developments in materials applied in sheet metal forming processes will be overviewed mainly from the viewpoint of automotive industry as one of the most important application fields. If we consider the main requirements in the automotive industry we can state that there are very contradictory demands on developments. Better performance with lower consumption and lower harmful emission, more safety and comfort are hardly available simultaneously with conventional materials and conventional manufacturing processes. These requirements are the main driving forces behind the material and technological developments in sheet metal forming: application of high strength steels, low weight light alloys and the appropriate non-conventional forming processes are the main target fields of developments summarized in this paper.


2012 ◽  
Vol 502 ◽  
pp. 36-40
Author(s):  
Ying Ke Hou ◽  
Shu Hui Li ◽  
Yi Xi Zhao ◽  
Zhong Qi Yu

Galling is a known failure mechanism in many sheet metal forming processes. It limits the lifetime of tools and the quality of the products is affected. In this study, U-channel stamping experiments are performed to investigate the galling behavior of the advanced high strength steels in sheet metal forming . The sheet materials used in the tests are DP590 and DP780. In addition to the DP steels, the mild steel B170P1 is tested as a reference material in this study. Experimental results indicate that galling problem becomes severe in the forming process and the galling tendency can be divided into three different stages. The results also show that sheet material and tool hardness have crucial effects on galling performance in the forming of advanced high strength steels. In this study, DP780 results in the most heaviest galling among the three types of sheet materials. Galling performance are improved with increased hardness of the forming tool.


2007 ◽  
Vol 344 ◽  
pp. 1-8 ◽  
Author(s):  
Manuel Lai ◽  
R Brun

In new vehicles development weight reduction is one of the most important driving force often conflicting with other missions which would require additional mass (crashworthiness, comfort, etc). The use of HSS, especially new grades with very high strength and good formability is the most competitive way to reduce weight. Nevertheless some limitations come from manufacturing HSS: springback, residual stresses, weldability should be taken into account in product development in order to avoid an expensive set up phase in the press shop and in the body shop. This paper focus on the recent experience achieved by Fiat in introducing HSS up to reach a share higher than 60% in weight applying and developing new methodologies to solve in the design phase any criticality arising from the use of this material.


2015 ◽  
Vol 812 ◽  
pp. 271-275 ◽  
Author(s):  
Miklós Tisza ◽  
Péter Zoltán Kovács ◽  
Zsolt Lukács ◽  
Antal Kiss ◽  
Gaszton Gál

Car manufacturing is one of the main target fields of sheet metal forming: thus sheet metal forming is exposed to the same challenges as the automotive industry. The continuously increasing demand on lower consumption and lower CO2 emission means the highest challenges on materials developments besides design and construction. As a general requirement, the weight reduction and light weight construction principles should be mentioned together with the increased safety prescriptions which require the application of high strength steels. However, the application of high strength steels often leads to formability problems. Forming Limit Diagrams (FLD) are the most appropriate tools to characterize the formability of sheet metals. Theoretical and experimental investigations of forming limit diagrams are in the forefront of todays’ research activities.


2012 ◽  
Vol 501 ◽  
pp. 94-98 ◽  
Author(s):  
Ying Ke Hou ◽  
Y.P. Li ◽  
Zhong Qi Yu ◽  
Yi Xi Zhao ◽  
Shu Hui Li

Galling is a known failure mechanism in sheet metal forming. It results in increased cost of die maintenance and scrap rate of products. For high strength steels, problems with galling are of major interest, since forming pressure is high as well as shear stress. In the last ten years, significant progress has been made on development and understanding of galling in sheet metal forming. In this paper, the main test apparatus and the methods used to reduce galling tendency are reported. And the galling mechanisms of galling are also analyzed.


2012 ◽  
Vol 548 ◽  
pp. 456-460 ◽  
Author(s):  
Gopi Alagappan ◽  
Syed H. Masood ◽  
Xuan Zhi Wang

In sheet metal forming, springback is defined as an elastic material recovery after unloading of the forming tools. Springback causes variations and inconsistencies of final part dimensions. Therefore prediction of springback is very important for production of precise products used in automobile and aerospace industries. There are various parameters involved in the process of sheet metal forming, including Young’s modulus, coefficient of friction, Poisson’s ratio, blank thickness, blank length, die radius, punch radius and blank holder force. The aim of this paper is to investigate the springback of a U-channel part by finite element analysis (FEA) and to identify the influences of important parameters on the springback of advanced high strength steels (AHSS) using numerical simulation.


2008 ◽  
Vol 587-588 ◽  
pp. 736-740
Author(s):  
Pedro Teixeira ◽  
Abel D. Santos ◽  
J. César de Sá ◽  
Augusto Barata da Rocha

The optimisation of sheet metal processes by using numerical simulations has become a key factor to a continuously increasing requirement for time and cost efficiency, for quality improvement and materials saving, in many manufacturing areas such as automotive, aerospace, building, packaging and electronic industries. The introduction of new materials brought new challenges to sheet metal forming processes. The behaviour observed with conventional steels may not be applied when using high-strength steels or aluminium alloys. Numerical codes need to model correctly the material and different constitutive equations must be considered to describe with greater accuracy its behaviour. This enhancement of material description may provide a better prediction of the forming limits, enabling an assessment of the influence of each forming parameter on the necking occurrence and the improvement of press performance. This paper presents two numerical approaches for failure prediction in sheet metal forming operations: one is the implementation of the Lemaitre’s ductile damage model in the Abaqus/Explicit code in accordance with the theory of Continuum Damage Mechanics and the other is the traditional use of FLDs, usually employed as an analysis of the finite element solution in which the necking phenomenon is carried out in the framework of Marciniak-Kuczinsky (M-K) analysis coupled with the conventional theory of plasticity. The previous strategies and corresponding results are compared with two experimental failure cases, in order to test and validate each of these strategies.


2013 ◽  
Vol 50 ◽  
pp. 253-266 ◽  
Author(s):  
B. Chongthairungruang ◽  
V. Uthaisangsuk ◽  
S. Suranuntchai ◽  
S. Jirathearanat

Sign in / Sign up

Export Citation Format

Share Document