Failure in sheet metal structures of ductile material is usually caused by one of, or a combination of, ductile fracture, shear fracture or localised instability. In this paper the failure of the high strength steel Docol 600DP and the ultra high strength steel Docol 1200M is explored. The constitutive model used in this study includes plastic anisotropy and mixed isotropic-kinematic hardening....

Abstract. In an ongoing quest to realize lighter vehicles with improved fuel efficiency, deformation characteristics of the material AA 6016 is investigated. In the first part of this study, material behavior of Al–Mg–Si sheet alloy is investigated under different process (temperature and strain rate) and loading (uniaxial and biaxial) conditions experimentally. Later, warm cylindrical cup deep...

an evolutionary structural optimization (eso) method is used for plastic design of frames. based on safe theorems some criteria are derived and made an effort to satisfy them during the optimization process. in this regard, equilibrium is checked and yield condition is gradually satisfied during the optimization process. in this method, the amount of used material and the stiffness for each ele...

The chemical composition, in situ ruminal degradability coefficients of dry matter (DM), and nutrient digestibility in sheep were evaluated for corn silage (CS) treated (fresh weight basis) with different levels of a commercial bacterial inoculant (I) as follows: (1) untreated CS (control); (2) CS + I at half of the recommended level; (3) CS + I at the recommended level (3  1010 colony forming...

Thin-walled tube bending has common applications in the automobile and aerospace industries. The rotary-draw-bending method is a complex physical process with multi-factor interactive effects and is one of the advanced tube forming processes with high efficiency, high forming precision, low consumption and good flexibility for bending angle changes. However, it may cause a wrinkling phenomenon,...

In this paper, a new approach is proposed for stress state - dependent flow localization in bifurcation failure model bounded through ductile damage in dynamically loaded sheets. Onset of localized necking is considered in phenomenological way for different strain rates to draw the forming limit diagram (FLD). Using a strain metal hardening exponent in the Vertex theory related to the strain ra...

Purpose: In this paper the experimental equipment and design of the system for deformation and forming force measuring by single point incremental sheet metal forming are described. Beside this the analysis results of the impact of the wall angle, tool rotation, vertical step size, tool diameter and lubrication on the magnitude of forming force and plastic logarithmic strain are presented. Desi...

In recent years, there has been a shift toward tissue-engineering strategies using stem cells for plastic and reconstructive surgical procedures. Therefore, it is important to develop safe and reproducible protocols for the extraction of adipose-derived stromal cells (ASCs) to allow cells to be stored in liquid nitrogen for future needs. The aspirated liposuction obtained from healthy donors we...

Aiming at the problems of ship plate forming spring-back in theory and experiment, combining the law of sheet metal forming, this paper puts forward a measurement and compensation method of spring-back outside plate of a ship based on the three dimensional NC (numerical control) pressing machine. First, we use Dynaform software for finite element analysis of springback prediction, and then esta...

Metal foils attract a large field of applications, e.g. in micro-technology they are being used for sensors, actors, micro-electro-mechanical systems and in medical devices. Conventional sheet metal forming processes are in principle applicable for metal foil forming. Reducing the sheet thickness to the order of micrometers, however, causes various scaling effects. Therefore, the know-how of co...