Prestress Force Identification for Externally Prestressed Concrete Beam Based on Frequency Equation and Measured Frequencies

Table 2

The corrected result of material parameters and frequencies.

	Material parameter		Frequency result (HZ) of (42)		Error (%)
	Elastic modulus (Mpa)	Density (kg/m^3)	Mode 1	Mode 2	Mode 1	Mode 2
Uncorrected	2.800 × 10^4	2500	38.347	143.998	−2.12	−4.31
Corrected	2.851 × 10^4	2583	37.545	138.079	0.01	−0.02

Note. Error denotes the (mode with corrected or uncorrected material parameter − test mode)/test mode × 100%, the same meaning in the Table 4.