RMOP

Applications

Metalforming on STAMPACK

BenchMark3 / SRail

Stampack is a metal forming simulation software intended, among other applications, for deep drawing simulation. RMOP is coupled with Stampack and using evolutionary algorithms and parallel computing, RMOP optimizes a set of design variables related to the manufactured part.

Some of the objective functions used to evaluate the results quality are:

Springback

Springback is defined as the small deformation that appears on a sheet metal after being molded due to material elastic recovery. In order to achieve maximum control of the final shape, springback is required to be minimum. Zero springback would mean that actual final form and mold's form are identical. RMOP allows to express springback as a function and to minimize it.

Safety

It is defined as the stress-strain state of a point of the material being formed. It characterizes each stress-strain state as: Strong Wrinkling, Wrinkling, Low Strain, Safe, Marginal, Thinning or Fail. Obviously, Fail or Strong Wrinkling are the least desirable states and Safe is the most desirable state.

Target point distance (TPD)

Every manufacturer provides a series of check points for the deformed metal sheet. Once the final shape is obtained, RMOP evaluates those distances and minimizes them.

Robust Multi-Objective Optimization Platform

CAE-based optimization of Stamping Processes for a Front Side Member. Appeared in Numisheet 2011 conference. The objective functions are maximum springback in a control point (to minimize) and average safety factor (to be in safe zone). The design variables are holding force and initial cut curve.

Numisheet 2011 Benchmark3 presentation [download]

Stampack simulation of deep drawing process

Optimization of a S-Rail stamping process. This benchmark was provided by Daimler AG in Numisheet 2008 conference (http://www.numisheet2008.ethz.ch/benchmarks). The objective functions are average springback (to minimize) and safety factor (to be in safe zone). The design variables are holding force and initial cut curve.

SRAIL presentation [download]

Fluid Dynamics on FEMUSS

Flap-Slat CFD

RMOP has been coupled with Computational Fluid Dynamics (CFD) solver. In particular, it has been used to find the optimum position of a slat (leading edge lift device) and a flap (trailing edge lift device) for a given airfoil in order to maximize the Lift to Drag ratio at takeoff and maximize the Lift at landing. Functions evaluated for both cases were:

CD/CL on take off (where CL and CD are lift and drag coefficients, respectively) (f1)
1/CL at landing speed (f2)

The aim was to achieve minimum values for both f1 (maximum CL/CD on take-off) and f2 (maximum CL on landing).

CFD presentation [Download]

Trencalòs Team

Trencalòs Team is a group of students from Escola Tècnica Superior d'Enginyeria Industrial i Aeronàutica de Terrassa (ETSEIAT, BarcelonaTech) focused on the design, construction and flying of model airplanes aimed to enter international competitions and conduct research in the field of Unmanned Aircraft Systems. The RMOP platform is used as a key tool in the development of the most suitable solution to each mission. The first implemented application has the improvement of the airfoil performance as its main goal keeping an easy-to-construct geometry. This aspect is a very important thing to be kept in mind because despite having an hypothetical optimum performance on the airfoil, if the geometry cannot be meticulously constructed, the real results will not meet its predicted behavior. The Team’s current work is focused in optimization by coupling different solvers (aerodynamic, structural and propulsive) and merging all the main design variables in an integrated design environment. RMOP is to be used in the upcoming Air Cargo Challenge airplane design. This competition will be held in Covilha, Portugal during August 2013. The results of the integrated optimization will be published after the competition closure due the competitive nature of this work.