scholarly journals Vibroacoustic Optimization of Stiffening Ribs and Damping Material Distribution on Sheet Metal Parts

2004 ◽  
Vol 11 (3-4) ◽  
pp. 271-280 ◽  
Author(s):  
M. Carfagni ◽  
P. Citti ◽  
L. Governi ◽  
M. Pierini
Keyword(s):  
Sheet Metal ◽  
Dynamic Stiffness ◽  
Efficient Design ◽  
Vehicle Noise ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Novel Approach ◽  
Damping Material ◽  
Basic Parameters ◽  
Stiffening Ribs

Vehicle noise and vibration levels are basic parameters in passenger comfort. Both static and dynamic stiffness of sheet metal parts is commonly increased by means of stiffening ribs. Vibrations are also reduced by adding a layer of damping material on the floor, the roof, the firewall and other parts of the vehicle. In common practice the panels to be treated are ribbed according to criteria based on the designer’s experience, rather than on well defined design procedures and are uniformly covered by a layer of damping material. However, these are not efficient design solutions, especially with regard to the effectiveness of vibration reduction and to weight containment. In this paper a novel approach to achieve an optimal distribution of stiffening ribs and damping material will be presented. The proposed method is based on a Genetic Algorithm (G.A.) procedure which takes into account both the vibroacoustic performance and the weight and cost reduction. A simple case study will be illustrated to demonstrate the capabilities of the developed procedure.

Erweiterung von Grenzen der Stegblechumformung*/Extension of limits of stringer sheet forming

2017 ◽  
Vol 107 (10) ◽  
pp. 689-694
Author(s):  
P. Prof. Groche ◽  
S. Köhler ◽  
H. Husmann ◽  
C. Kurpiers
Keyword(s):  
Sheet Metal ◽  
Process Chain ◽  
Base Plane ◽  
Forming Process ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Flat Sheet ◽  
Heat Treated ◽  
New Process ◽  
Stiffening Ribs

Stegbleche sind flächige Bauteile, die senkrecht zur Grundblechebene Versteifungsrippen aufweisen. Die Herstellung von räumlich gekrümmten Stegblechen findet durch Blechverzweigung im ebenen Zustand und anschließender Umformung in die Zielgeometrie statt. Beim Umformprozess ergeben sich neue Prozessgrenzen wie Risse oder Beulen an den Stegen. Dieser Fachbeitrag zeigt, wie wärmebehandelte, höhenveränderliche, vorgespannte oder im Prozess unterstützte Stege diese Grenzen um bis zu 200 % erweitern.   Stringer sheets are flat sheet metal parts, which have stiffening ribs vertical to the base plane. The production of spatially curved stringer sheets takes place in a process chain of sheet metal bifurcation in the flat state and a subsequent forming process. During this forming process, new process limits such as cracks and wrinkling occur due to the stringers. This article presents how heat-treated, height-adjusted, pre-stressed or supported stringers exceed these limits by up to 200 %.

Experimental and Numerical Analysis of Blanking for Thin Sheet Metal Parts

2001 ◽  
Vol 4 (3-4) ◽  
pp. 319-333
Author(s):  
Vincent Lemiale ◽  
Philippe Picart ◽  
Sébastien Meunier
Keyword(s):  
Numerical Analysis ◽  
Sheet Metal ◽  
Thin Sheet ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Thin Sheet Metal

Analysis of Nonlinear Variation Accumulation in Auto-Body Assembly Process

Manufacturing ◽  
2002 ◽  
Author(s):  
Jun Lian ◽  
Zhongqin Lin ◽  
Fusheng Yao ◽  
Xinmin Lai
Keyword(s):  
Sheet Metal ◽  
State Equation ◽  
Assembly Process ◽  
Transformation Mechanism ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Accumulation Mechanism ◽  
Auto Body ◽  
Non Gaussian ◽  
Geometrical Dimensions

In the assembly process of auto-body, variations in the geometrical dimensions of sheet metal parts and fixtures are inevitable. These variations accumulate through the multi-station assembly process to form the dimensional variations of the final products. Compared with the assembly of rigid parts, the assembly process of the elastic parts is more complex because the variation accumulation patterns rely much on the variations of fixture, jointing methods and mechanical deformation. This paper aims at analyzing the variation transformation mechanism and accumulation characteristics for the assembly of sheet metal parts based on the analysis of dimensional coordination relations among parts and fixtures. Finite element method (FEM) and Monte-Carlo Simulation (MCS) were used to analyze the effect of jointing contact on variation transformation, while a state equation was developed to describe the variation accumulation mechanism. The result of the analysis indicates that the main characteristics of elastic assembly jointing are the overlap jointing methods and elastic contacts action. The fact that the variation transform coefficients (VTC) are variable makes the assembly variation distribution Non-Gaussian even if the dimension variation of parts is Gaussian distribution. The analysis conclusions have potential value for more reasonable tolerance synthesis of elastic parts assembly.

Aanalysis of springback phenomenon in pipe bending

2014 ◽  
Vol 11 (3) ◽  
pp. 229-232
Author(s):  
Rahul Hingole ◽  
Vilas Nandedkar
Keyword(s):  
Sheet Metal ◽  
Research Work ◽  
Deep Understanding ◽  
Beam Theory ◽  
New Approach ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Before And After ◽  
Forming Tools ◽  
Pipe Bending

The term springback is defined as the change in geometry of a component after forming, when the forces are removed from forming tools. As springback affects the final shape of the part, it can lead to significant difficulties in the assembly of component when springback is not proper. This problem leads to fabrication of inconsistent sheet metal parts; the elastic strain recovery in the material after the tooling is removed. Bendingis the plastic deformation of metals about a linear axis called the bending axis with little or no change in the surface area. Bending types of forming operations have been used widely in sheet metal forming industries to produce structural stamping parts such as braces, brackets, supports, hinges, angles, frames, channel and other nonsymmetrical sheet metal parts. Among them, quite a few efforts have been made to obtain a deep understanding of the springback phenomenon. The beam theory has been applied to formulate the curvature before and after loading of pipe. This research work has focused on study effect of springback effect with a new approach. The ANSYS software is used to analyze spring back effect. The detail study of this springback effect is presented in this paper.

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