Determination of Material/Geometry of the Section Most Adequate for a Static Loaded Beam Subjected to a Combination of Bending and Torsion

Abstract

The acceleration of industrial machines mobile parts has been increasing over the last few years, due to the need of higher production in a short period of time. The machines were dimensioned for a lower value of acceleration, which means there is not enough rigidity for the correct operation at much higher accelerations. Nowadays, the accelerations can be near 12 times the acceleration of gravity. There is the need of improving rigidity to make possible the correct machine operation without undesired vibrations that can ultimately lead to failure. The main applications of this work are plotters and laser cutting machines. To improve rigidity, one must improve the relevant material properties, and the relevant geometric variables of the model.[1] A novel Finite Element Model Updating methodology is presented in this paper. The considered models were : a ribbed plate and a tubular beam. The models were built by means of the Finite Element Method (FEM), and MATLAB was used to control the optimization process, using a programming code. Both material properties and geometric parameters were optimized. The main aim of the materials modeling is to know how the value of the objective function changes with the value of the material properties. Materials selection was performed, using material selection charts, to select the best material for the application. The value of these properties was not in the catalogue, and the properties used to perform the material selection were related to a material sub-class, Eg. Steel. The final material selection determined the best specific material for the application, and that material was mechanically tested. The mechanical tests performed were: Tensile Test and Extensometry Test, to obtain the relevant material properties, mainly Young Modulus, Poisson Coefficient and Yield Stress. The deflection of the optimized models reduced strongly in comparison to the initial models.

Sensitivity Analysis of Internally Reinforced Thin-Walled Hollow-Box Beams Subjected to Uncoupled Bending and Torsion

“…One of them goes through selecting a material having higher Young's modulus value. The other is to modify the inertia moment of a considered part [1,2]. This can be achieved by inserting ribs in the longitudinal and/or transversal directions and/or webbing.…”

“…The lack of stiffness in structures causes an increase in friction and wear in the mobile parts, but excessive vibrations remain the main prob-lem, sometimes disturbing smooth operation. A research regarding sensitivity analysis for the same application of an industrial machine was performed earlier by one of the authors, [1]. Optimization for structural applications was also performed in [2].…”

“…A research regarding sensitivity analysis for the same application of an industrial machine was performed earlier by one of the authors, [1]. Optimization for structural applications was also performed in [2]. The authors optimized tubular beams for industrial machine applications in both these works.…”

Experimental Validation of a Novel Thin-Walled Beam Prototype

“…Nowadays, it can be near 12 times higher than the acceleration of gravity. There is the need of improving rigidity to make possible the correct machine operation without undesired vibrations that can ultimately lead to failure [1,2]. Having these considerations in mind, effective geometries have already been studied and similar geometries to https://doi.org/10.2478/mme-2018-0001 the prototype of this work were tested for feasibility [3].…”

Structural Optimization Coupled with Materials Selection for Stiffness Improvement

“…Silva and Meireles developed a Finite Element Model Updating methodology for static analysis, where the main aim was to optimize the mechanical behaviour of steel objects subjected to bending and torsion uncoupled loadings [10,11]. Some authors applied optimization methods to beams of various cross-sections manufactured by cold forming in order to optimize relevant geometric variables of the structures [12].…”