For an existing reinforced concrete or steel structure the evaluation of the stiffness matrix may be hampered by certain physical limitations such as material deterioration resulting from prolonged use an adverse or in a corrosive environment. The following is a method that allows the determination of the member stiffness of an indeterminate truss through a minimization technique of a properly constructed Error Function. Thus exact sectional and material properties do not have to be known a priori.

For an existing reinforced concrete or steel structure the evaluation of the stiffness matrix may be hampered by certain physical limitations such as material deterioration resulting from prolonged use an adverse or in a corrosive environment. The following is a method that allows the determination of the member stiffness of an indeterminate truss through a minimization technique of a properly constructed Error Function. Thus exact sectional and material properties do not have to be known a priori.