A Damage Prognosis Method of Girder Structures Based on Wavelet Neural Networks

Table 5

Parameters change before and after updating based on the response surface method.

Updated parameters	𝐸0	𝐸1	𝐸2	𝐸3	𝐾1	𝐾2	𝐾3
	(×10^4 MPa)	(×10^4 MPa)	(×10^4 MPa)	(×10^4 MPa)	(×10^6 N/m)	(×10^6 N/m)	(×10^6 N/m)
2012	3.6	3.5	3.2	2.5	0.6	3.1	3.1
2013	3.3	2.8	3.2	2.2	0.9	4.7	1.7
Rate (%)	−8.8	−19.8	−1.9	−12.4	50.0	48.4	−43.3

Notice: 𝐸₁ is the elasticity modulus of webs in the 2nd, 3rd, and 5th spans; 𝐸₂ is the elasticity modulus of web in the 4th span; 𝐸₃ is the elasticity modulus of bottom slab in the 2nd, 5th spans; 𝐸₀ is the elasticity modulus of the other parts; 𝐾₁ is transverse spring stiffness at the support and expansion joints; 𝐾₂ is the longitudinal spring stiffness at the support; 𝐾₃ is the longitudinal spring stiffness at the expansion joints.