In this study, numerical and experimental results of deep drawing process were compared. Drawn part, used in automotive industry was drawn and measured using ARGUS measurement system, which works on a digital image correlation method (DIC). In order to optimize and verify accuracy of a numerical simulation results, this process was modeled in two codes which work on principle of the finite element method (FEM). Two types of FEM codes were used. Code which works on base of both, implicit and explicit time integration scheme, were used for calculation. Results were compared and discussed.
To assess formability in sheet forming, experimentally determined Forming Limit Curves (FLC) are often used. These conventional FLCs represent the forming limits (i.e. onset of necking) of a sheet material subjected to in-plane deformation or almost in-plane deformation. A widely used approach to experimentally determine the onset of necking of sheet material subjected to in-plane and almost in-plane deformation is formulated in ISO 12004. The aim of this work is to investigate limit strains for deep drawing quality sheet metal of HX180BD made by ArcelorMittal with nominal thickness 0.6 mm. The FLC curve has been measured by implementation of Nakajima test on universal testing machine Erichsen 145-60. The Nakajima test has been measured according to EN ISO 12004-2. Limit strains have been measured using 3D photogrammetric system ARAMIS by GOM. Forming limit curve was evaluated both the section method and the time dependent technique. The resulting experimental FLC curves were compared. With the time based method for the determination of FLC a greater strain values was achieved.
Nowadays is a possible to implement numerical simulation and photogrammetric inspection to the complex process chain of inspection. In the recent years there has been significant progress in accuracy improving of these methods of inspection in pre-production or post-production stage of manufacturing. This article discusses these two methods from sensitivity and comparison point of view. Most attention has been paid to the photogrammetric method and his sensitivity to using different approaches. Results were compared with the result of numerical simulation and experiment. Numerical simulation was performed in static implicit finite element code Autoform. For this purpose, GPS cover of galvanized steel of DQ category was used for inspection. In this paper was proved that photogrammetric method of strain measurement is highly sensitive on the various external factors. Further results and findings are included in the next chapters of this paper
The most common problem in area of sheet metal forming technology is a problem of achieving accurate and repeatable shapes of drawn and bent parts. This phenomenon is caused by the elastic springback. Springback can be defined as an elastically-driven change of shape of the deformed part upon removal of external loads. Several technological parameters influence amount of springback, between these belong friction coefficient, blankholder force, different geometry of tools, etc. In this paper is presented this topic, and also numerical simulation of this process. For an experimental process were used two high-strength steels. Steel with TRIP effect and dual phase steel DP 600. Numerical simulation was performed in the static implicit code Autoform. Results were compared and discussed.
Redistribution of residual stresses in a stamped sheet metal leads to the springback phenomenon. Springback phenomenon is well predicted for some mild steel materials, but not for steels with higher strengths. Nowadays, one of the most used tools to stamping optimization is usage of numerical simulations. In this paper was investigated sheet metal behavior under cyclic tension-compression test. Special fixture which serves as a buckling prevention of sheet metal in the compression phase of measuring stress-strain curve was designed. Obtained stress-strain curve was used to the definition of kinematic hardening model in numerical simulation. This model was verified with the real experiment in deep drawing process.
Springback is a common phenomenon in sheet metal forming, caused by the elastic redistribution of stresses during unloading. It has been recognized that springback is essential for the design of tools used in sheet metal forming operations. A finite element method (FEM) code has been used to analyze the sheet metals V-bending process. In the work, three types of steels TRIP, AHSS and mild steel were used. Normal anisotropic material behavior has been considered. A contact algorithm for arbitrarily shaped rigid tools has been realized by means of accurate approach. This paper describes a robust method of predicting springback under bending and unbending of sheets. Constitutive models, aimed at predicting the final shape of the sheet after the springback by varying the setting of the operational parameters of the forming process, were discussed. The accuracy of the model was verified by comparison with results of PAM-STAMP 2G package and experimental results.
Springback is one of the most important problems that should be taken into consideration during design of sheet metal forming process with the increasing application of advanced high strength steels and light-weight alloys. The degree of springback experienced with the latest generation materials is so high, and the materials so strong, that it is not possible to eliminate the springback in the prototyping. It becomes mandatory to compensate for springback as part of the draw die design, which is usually carried out through numerical simulation. The springback behavior of three categories of sheet steels (TRIP, HSLA and mild steel) with thicknesses ranging from 0.75 to 0.85 mm was investigated by means of the cyclic U-bending test. This phenomenon can be defined as an elastically-driven change of shape of the deformed part upon removal of external loads. Steel sheets were bent on the two different die radii and after first cycle were bent reverse. The influence of die radius on amount of springback of the steels was considered. Value of the springback angle change after the first and second cycle was measured. The change of values of angles between cycles is caused by the Bauschinger effect. This process was investigated experimentally and numerically. Numerical investigation was performed in static implicit finite element code Autoform.
Modeling sheet metal forming operations requires understanding of the plastic behavior of the sheet metal along the non-proportional strain paths. Measurement of hardening under reversed uniaxial loading is because of its simplicity very effective mechanical test to achieve several important features of material behavior. With the reversed uniaxial loading can be examined features as Bauschinger effect, work hardening stagnation, permanent softening etc., which are necessary to defined kinematic hardening in the numerical simulations. The biggest problem of uniaxial reversed loading is buckling of the sheet metal during the compression phase. In this article is described development of the simple fixture, used for the reversed uniaxial loading and results of tension-compression test for the steel DP 600 in various pre-strain levels are specified.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.