Nowadays, with extending applications of bi-layer metallic sheets in different industrial sectors, accurate specification of each layer is very prominent to achieve desired properties. In order to predict behavior of sheets under different forming modes and determining rupture limit and necking, the concept of Forming Limit Diagram (FLD) is used. Optimization problem with objective functions an...

The purpose of this investigation is to examine the viability of using the sheet metal for forming applications. Forming limit diagram (FLD) composed of negative and positive minor strain with respect to major strain which occurs at directional zero strain with the critical thickness of sheet metal. The negative minor strain region of FLD is predicted by localized necking. However there is no d...

In this research, Forming Limit Diagrams for supertension sheet metals which are using in automobile industry have been obtained. The exerted strains to sheet metals have been measured with four different methods and the errors of each method have also been represented. These methods have been compared with together and the most efficient and economic way of extracting of the exerted strains to...

The conventional theoretical forming limit diagram (FLD) based on the plane stress state has defects due to neglect of in thickness direction sheet. It is urgent study FLD which considers direction. Through finite element simulation, it further confirmed that will be induced deformation process. At same time, effect not as always applied during Based Modified Maximum Force Criterion (MMFC) inst...

Applying ultrasonic vibration in sheet metal forming can change its mechanism and improve formability. The uniaxial tensile bulging limit experimental setups were designed to study the relationship induced by excitation, results under different conditions analyzed. It was found that has effects on left right sides of diagram (FLD). Under same frequency, maximum increment major strain is about 9...

An enhanced unfolding Inverse Finite Element Method (IFEM) has been used together with an extended strain-based forming limit diagram (EFLD) to develop a fast and reliable approach to predict the feasibility of the deep drawing process of a part and determining where the failure or defects can occur. In the developed unfolding IFEM, the meshed part is properly fold out on the flat sheet and tre...

The forming limit diagram (FLD) is probably the most common representation of sheet metal formability and can be defined as the locus of the principal planar strains where failure is most likely to occur. Low carbon steel sheets have many applications in industries, especially in automotive parts, therefore it is necessary to study the formability of these steel sheets. In this paper, FLDs, wer...

more recently, titanium and aluminum alloys are gaining more interests to be implemented in hydro-forming applications. it is necessary to predict forming limits for these sheet alloys. forming limits play an important role in metal forming processes. forming limit diagrams, present the limit strains for various linear strain paths. in other hand, forming limit curve (flc), illustrates localize...

Sheet metal forming boundaries are established using the limit diagram (FLD). The Nakajima and Marciniak tests, which based on stretching a material punch, most commonly used methods for determining FLD or fracture (FFLD). results usually evaluated by calculating local strain, strain rates, specimen thickness reduction strain. When amount of experimental is insufficient, miniaturization testing...