Compared with the conventional manufacturing of aluminum sheet metal, the forming of so called Tailored Heat Treated Blanks (THTB) enables the production of complex aluminum sheet metal parts [1], [2]. The reasons for the lower forming behavior of aluminum alloys are well founded in the material properties. Especially smaller values for uniform elongation (< 30 %) and vertical anisotropy (< 1) ...

The objective of this study was to evaluate the influence of microstructure on the susceptibility to high-cycle fatigue (HCF) failure in Ti–6Al–4V following foreign-object damage (FOD), specifically by comparing a fine-grained bi-modal microstructure with a coarse grained lamellar microstructure. FOD was simulated by high-velocity impacts of steel spheres on a flat surface. This caused a marked...

In this contribution we go through the developments that in the years from 1968 to about 1974 led from the Veneziano model to the bosonic string theory. They include the construction of the N -point amplitude for scalar particles, its factorization through the introduction of an infinite number of oscillators and the proof that the physical subspace was a positive-definite Hilbert space. We als...

The seismic performance of elliptic braced moment resisting frame (ELBRF) is assessed here and is found that the structural behavior is improved and is of free of architectural space. The demand for seismic performance of ELBRF is estimated through conventional pushover methods of 3, 5, 7, and 10-story ELBRF frames and they are compared with special moment resisting frames (SMRF) and X-Braced C...

In hot forming process, the workpiece undergoes plastic deformation at high temperature and the microstructure of the workpiece changes according to the plastic deformation. These changes affect the mechanical properties of workpiece. In order to optimize this process, both the plastic deformation of workpiece and its microstructural changes should be taken into consideration. Since material be...

This paper investigates the forming of sheet metal forming under cycling loading by considering the Bauschinger effect. Different proposed plasticity models which can handle this kind of deformation process have been reviewed in details. For instance, isotropic, kinematic and combined forms in the linear and non-linear cases including the well-known Yoshida and Chaboche's models have been studi...

Forming limit diagrams (FLDs) are calculated based on both the Marciniak and Kuczynski (M-K)  model and the analysis proposed by Jones and Gillis (J-G). J-G analysis consisted of plastic deformation approximation by three deformation phases. These phases consisted of homogeneous deformation up to the maximum load (Phase I), deformation localization under constant load (phase II) and local necki...

Sheet metal forming operations play a crucial role in the manufacturing process of various products. However, challenge plastic instability, which often leads to defective products, continues persist this field. It is important consider parameters, such as Forming Limit Diagram (FLD), overcome issue during manufacturing. The Aluminium Alloy (AA2014) has been employed study investigate its forma...

Abstract Multi-fidelity optimization, which complements an expensive high-fidelity function with cheaper low-fidelity functions, has been successfully applied in many fields of structural optimization. In the present work, exemplary cross-die deep-drawing optimization problem is investigated to compare different objective functions and assess performance a multi-fidelity efficient global techni...