Testing of semi-rigid unbraced frames for calibration of second-order inelastic analysis

Compound-element modeling accounting for semi-rigid connections and member plasticity

“…14(a). Also shown are the test results [16] and the computed results from a refined plastic hinge analysis method called PHINGE [2]. It is obvious at lower loading levels (H < 35 kN) that the load-deflection results found by this study (heavy-solid curve) and the PHINGE method (dashed curve) are in good agreement with each other and the test results (dotted curve).…”

“…Conversely, a connection is assumed to be flexible if the following condition is satisfied, R ce L EI ≤ 0.5 (or r c ≤ 0.143 for either a braced or an unbraced frame). (16) When elastic stiffness R ce or corresponding stiffness factor r c is located between the values defined by Eq. (14) or (15) and (16), a semi-rigid connection is attained.…”

“…Note that the stiffness criteria defined in Eqs. (14) through (16) are related to member length L. If only the member length changes, the connection category changes according to the stiffness criteria. For instance, if R ce L/EI = 9 for a braced frame, then the connection is rigid; however, when member length L changes to 0.5L, the corresponding stiffness ratio becomes 0.5R ce L/EI = 4.5, and the same connection becomes semi-rigid.…”

“…The objective of the first example concerning a semi-rigid portal frame is to compare the results obtained by this study with those obtained from experimental testing [16]. The second example illustrates a comparison study of a one-bay by two-storey semi-rigid frame designed by Chen et al [2].…”

“…12, for which experimental test results are available in the literature [16], the properties of the beam are: area A = 4740 mm 2 , moment of inertia I = 5547 × 10 4 mm 4 , plastic modulus Z = 485 × 10 3 mm 3 , normal yield stress σ y = 345 MPa, and shear yield stress τ y = 199 MPa (based on the von Mises criterion). The properties of the two columns are: area A = 7600 mm 2 , moment of inertia I = 6103 × 10 4 mm 4 , plastic modulus Z = 654 × 10 3 mm 3 , and yield stresses σ y = 336 MPa and τ y = 194 MPa.…”