Test function: The Nowacki Beam
Description
This function is a variation of the classic multiobjective optimization problem (NOWACKI, 1980). In this problem the aim is to design a tip loaded cantilever eam for minimum crosssectional aera and lowest bending stress subject to a number of constraints.
Usage
1 2 3  nowacki_beam(x, g = c(5, 240, 120, 10, 2), l = 1500, F = 5000,
E = 216620, G = 86650, v = 0.27, box = data.frame(b = c(10, 50), h =
c(20, 250)))

Arguments
x 
vector of length 2 correspon the normalized beath and height of the beam 
g 
vector of lenght 5 containing the upper limits of each constraint 
l 
numeric length of the beam 
F 
numeric force applied at the beam tip 
E 
numeric elastic longitudinal moduli 
G 
numeric elastic transversal moduli 
v 
numeric poison ratio 
box 
data.frame structure containing the upper and lower limits for

Value
vector of objective and constrain responses
References
Forrester, A., Sobester, A., & Keane, A. (2008). Engineering design via surrogate modelling: a practical guide. John Wiley & Sons.
Examples
1 2 3 4 5 