efficiency, only one FEM run was required for checking
the feasibility of the optimum solution under specific
quality constraints. This implies that the current methodology
is considered practical and provides a guide
towards the application of the optimum energy efficient
solution of the cold roll forming process.
A U-channel profile was demonstrated for the calculation
of a feasible optimum energy solution. The Optimum
energy efficient solution was calculated through
the robust design algorithm along with the control and
noise factors orthogonal arrays. The production rate
was192.41 parts per minute, and the total power input
to the electric motor was 29.75 W per meter of the
produced profile, which yielded to an energy efficiency indicator
of 0.3283 m/J-h). The number of roll stations required
for the optimum energy efficient solution was
ten. The responsibility of the cold roll forming process
parameters (control factors) on energy efficiency was
calculated, with the major parameter to be the roll
gap, the rollers radius, and the bending concept with
responsibility of 30.96, 24.77, and 23.62 %, respectively.
The optimum energy efficient solution EEF_V1 feasibility
was checked through an FEM analysis. The
results of the quality characteristics predicted that
EEF_V1 was not sufficient, and alternations to the cold
roll forming line were induced as having resulted into a
second EEF_V2 solution. Such alternations improved
quality of the roll formed product, while the energy
efficiency indication was decreased by only 1.6 %.
Quality improvements comprised the decrease of longitudinal
strains by about 15 % (on average), thickness
reduction decrease by 8.4 %, major strains peak decrease
by 13.9 %, and cross-sectional dimensional error
peak decrease of 45.3 %. Finally, a benchmarking analysis
was implemented having as benchmark the
manufacturing of a U-channel profile on a photovoltaic
mounting frame. There was a comparison of the results
and a demonstration of the potential energy consumption
along with the financial savings.
Acknowledgments The work reported in this paper was partially
supported by CEC/FP6 NMP Programme, “Integration multifunctional
materials and related production technologies integrated into
the automotive industry of the future-FUTURA” (FP6-2004-NMP-NI-
4-026621).