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...

Growing demand for sustainable products has led to increased interest in the use of paperboard as a structural material. Paperboard products are almost exclusively manufactured by embossing, pulp molding, and bending processes. Other well-known forming methods, such as deep or stretch drawing, are only rarely applied to paperboard. This is primarily ascribed to the lack of knowledge concerning ...

forming limit diagram (fld) is an important diagram by which the formability of sheet metals is studied. strain rate is a very effective parameter influencing the fld which is, in turn, influenced by the forming velocity. in this work, forming limit diagram for st14 was investigated both experimentally and numerically. in addition, the effect of forming velocity was studied and the experiments ...

Two-layer metallic sheets have wide applications in aerospace, marine, automotive and domestic industries due to their superlative characteristics. In this paper, the formability of two-layer sheet is investigated through analytical, experimental and numerical approaches. An analytical model is developed based on Marciniak-Kuczynski method associated Hill’s non-quadratic yield criterion. Formin...