Stamping

About: Stamping is a research topic. Over the lifetime, 22501 publications have been published within this topic receiving 83554 citations.

Apparatus and method for stamping a surface

Abstract: An apparatus (100) including a support structure (104), a flexible stamp (106) having a stamping surface (110) including a predetermined pattern disposed opposite the support structure (104), a pressure controlled chamber (112) disposed above the support structure (104), and a mechanical attachment (114) affixed to the flexible stamp (106). A method is provided for stamping the surface (101) of an article (102) including the steps of i) placing the article (102) on the support structure (104) within the pressure-controlled chamber (112), ii) wetting the stamping surface (110) with a solution containing a self-assembled monolayer-forming molecular species, iii) aligning alignment patterns (118) on the flexible stamp (106) with alignment patterns (124) on the surface (101) of the article (102), iv) controllably contacting the wetted stamping surface (110) with the surface (101) of the article (102) by changing the pressure differential across the flexible stamp (106) so that contact commences at the center of the flexible stamp (106) and proceeds outwardly in a controlled manner, and v) removing the stamping surface (110) from the surface (101) of the article so that a self-assembled monolayer (134) having the predetermined pattern is formed on the surface (101) of the article (102).

Composite laminate automotive structures

Abstract: A side impact beam (100) for an automotive body construction has an outer structural portion (102) of mild steel or nonheat-treated high-strength steel, and an inner reinforcement stamping (104) of ultrahigh-strength steel separated by a thin layer of structural foam (106) of thermally expandable resin-based material including hollow microspheres. The inner reinforcement (104) is localized at the midpoint of the side impact beam (100). A vehicle bumper (200) for a motor vehicle has an outer structural portion (202) of mild steel or nonheat-treated high-strength steel, and an inner reinforcement stamping (206) of ultrahigh-strength steel separated by a thin layer of structural foam (208) of thermally expandable resin-based material including hollow microspheres. The inner reinforcement (206) is localized at the midpoint of the vehicle bumper (200).

Commercial scale production of Fe-6.5 wt. % Si sheet and its magnetic properties

Abstract: Commercial scale production of a Fe‐6.5 wt. % Si sheet has been successfully developed. Presently manufactured sheets are in coil form, whose thickness ranges from 0.1 to 0.5 mm with a maximum width of 400 mm. Magnetic properties of the manufactured sheet have been investigated. The permeability of Fe‐6.5 wt. % Si sheet is about 10 times higher than the conventional nonoriented silicon steel sheet. The core losses are less than half the conventional, and even less than that of the grain‐oriented silicon steel sheet at frequencies over 400 Hz. Superior soft magnetic properties are attributed to the low magnetostriction and high electric resistivity of this alloy. It is well known that the Fe‐6.5 wt. % Si alloy has poor ductility in conventional mechanical work. But investigation of the forming conditions has enabled the stamping and bending of alloy sheets. Low core losses and high permeability make Fe‐6.5 wt. % Si sheet adequate for motor cores, transformer cores operating at high frequencies, and magnetic shielding. Application to the micromotor core shows that Fe‐6.5 wt. % Si sheet reduces the consumption of no‐load electric current by 25% in comparison with the conventional silicon steel.

Numerical failure analysis of a stretch-bending test on dual-phase steel sheets using a phenomenological fracture model

Abstract: Advanced High Strength Steels (AHSS) are increasingly used in automotive industry due to their superior strength and substantial weight advantage. However, their compromised ductility gives rise to numerous manufacturing issues. One of them is the so-called ‘shear fracture’ often observed on tight radii during stamping processes. Since traditional approaches, such as the Forming Limit Diagram (FLD), are unable to predict this type of fractures, great efforts have been made to develop failure criteria that could predict shear fractures. In this paper, a recently developed Modified Mohr–Coulomb (MMC) ductile fracture criterion ( Bai and Wierzbicki, 2010 ) is adopted to analyze the failure behavior of a Dual Phase (DP) steel sheet during stretch-bending operations. The plasticity and ductile fracture of the present sheet are fully characterized by a Hill’48 orthotropic model and a MMC fracture model, respectively. Finite element models with three different element types (3D, shell and plane strain) were built for a Stretch Forming Simulator (SFS) test ( Shih and Shi, 2008 ), numerical simulations with four different R / t values (die radius normalized by sheet thickness) were performed. It has been shown that the 3D and shell element simulations can predict failure location/mode, the upper die load–displacement responses as well as wall stress and wrap angle at the onset of fracture for all R / t values with good accuracy. Furthermore, a series of parametric studies were conducted on the 3D element model, and the effect of tension level (clamping distance), tooling friction, mesh size and fracture locus on failure modes and load–displacement responses were investigated.