Editor’s Note

The opening paper in this issue, by Tan, Dyke Richardson, and Abdullah, investigates “Integrated Device Placement and Control Design in Civil Structures Using Generic Algorithms.” An integrated technique for control device placement and controller design was proposed and demonstrated. The approach employs generic algorithms to identify an optimal solution to the placement problem. Dutta, Das, and Roy present “Seismic Behavior of Code-Designed Bidirectionally Eccentric Systems.” The authors address the inelastic response of bidirectionally asymmetric structures designed in accordance with existing building code standards. Results of the study demonstrate inadequacies in design code provisions to adequately account for seismic torsional vulnerability of bidirectionally eccentric systems. Precast concrete hollow-core slabs constructed without a structural concrete topping is the subject of the next paper, “Waved Joint for Seismic-Resistant Floor Diaphragms,” by Menegotto and Monti. Results of the study indicate that the waved joint profile provides adequate diaphragm capability in a seismic environment. The cyclic loading performance of links in structural steel frames is investigated by Okazaki et al. in “Experimental Study of Local Buckling, Overstrength, and Fracture of Links in EBFs.” The authors present design recommendations to enhance the structural performance of links under seismic loading. Nagayama, Fujino, and Ikeda describe a new structural identification method in their paper “Structural Identification of Nonproportionally Damped Systems and Its Application to Full-Scale Suspension Bridge.” The authors verify that the method can precisely determine the dynamic characteristics of both lower and higher vibration modes.

The next group of papers deals with analysis and design of structural steel members. Richards and Uang conducted an analytical study to investigate the influence of the flange width-thickness ratio on the rotation capacity of links in eccentrically braced frames, which they present in “Effects of Flange Width-Thickness Ratio on EBF Link Cyclic Rotation Capacity.” Results indicate that a relaxation of the flange width-thickness ratio requirement in the current AISC seismic design provision is justified. The design of angle section steel columns with slender legs is addressed by Rasmussen in the paper “Design of Angle Columns with Locally Unstable Legs.” The author reports that the local buckling mode is identical to the torsional mode, and that traditional design procedures are overly conservative because they account for the torsional (local) buckling mode twice. “Strength of Welded Connections in G450 Sheet Steel,” by Teh and Hancock, presents test results to verify design rules in the North American Specification for Cold-Formed Steel Structural Members. “Buckling Analysis of Cold-Formed Steel-Lipped Angle Columns,” presented by Young and Ellobody, describes the buckling behavior of this structural element through a comprehensive finite-element analysis. The column strengths predicated by the finite-element results are compared with design strengths calculated using several existing design specifications.

A mathematical nonlinear model that uses the concepts of high-order theory, and incorporates nonlinear and inelastic shear stress-shear angle behavior of adhesive material, is investigated by Rabinovitch in “Bending Behavior of RC Beams Strengthened with Composite Materials Using Inelastic and Nonlinear Adhesives.” Results of the study imply that the use of such adhesive materials improves the overall load-carrying behavior of the strengthened beam, increases ductility, provides the mechanism for the formation of plastic hinges and reduces the shear stress near the ends of the bonded strip. Liang et al. use the finite-element method to investigate the flexural and shear strengths of composite beams under combined bending and shear in “Strength Analysis of Steel-Concrete Composite Beams in Combined Bending and Shear.” Design models for vertical shear strength, including contributions from the concrete slab and composite action for the ultimate moment-shear interaction, are proposed. A method for the study of the nonlinear material response of masonry wall systems, subject to gravity and horizontal loads, is proposed by Roca, Molins, and Mari in “Strength Capacity of Masonry Wall Structures by the Equivalent Frame Method.” The use of the method is demonstrated in the analysis of large historical structures, and for simulating potential repair and restoration scenarios.

Lutes et al. present the development of an optimal protocol for stress range/number of cycle’s life testing in “Optimal S/N Fatigue Testing for Structural Stochastic Service Loads.” The mathematical results apply to any problem in which there is uncertainty about the properties of the specimen and/or the stress ranges that will be applied under service loads. Numerical results demonstrate that the optimal S/N testing procedure may depend quite significantly on stress ranges in the service loads. “Structural Response and Reliability Estimates: A Slepian Model Approach,” by van de Lindt and Niedzwecki, investigates the practicality of using a slepian mode to simulate earthquake excitation and structural response behavior of structures during strong ground-motion earthquake acceleration records. A procedure that yields reasonable response predictions and allows one to bound estimates for conditional structural reliability is presented. Zhu et al. conducted an experimental study to investigate “Buckling of OSB Wehlad Wood I-Joists.” Both lateral buckling and local buckling were considered in the study. Results of the investigation indicate that lateral buckling is closely related to the span, flange, and arrangement of lateral restraints; local web buckling is most likely to occur at the supports or beneath a loading point.

This issue also includes a technical note, a discussion, and a closure. The technical note, by O’Rourke and Kuskowski, presents a method for evaluating “Snow Drifts at Roof Steps in Series.” The method is based upon current provisions in the current ASCE 7 Load Standard and yields conservative estimates for drift at a downward leeward or windward step. The discussion is by Bakhshi and Tavallali on the paper “Bound Earthquake Input Energy,” by Takewaki. The discussers raise two concerns: (1) the earthquake input energy to a SDOF system does not necessarily reach its maximum value at the end of the record, and (2) the term used in the discussed paper to obtain earthquake input energy is the same as the relative earthquake energy defined in a previous independent study. In response to the first point, the author argues that the discussers misinterpreted his definition of the earthquake energy input. As to the second point raised, the author responds that the discusser’s approximation of the energy transfer function and their approximation of the Fourier amplitude spectrum are not based on any physical meaning of those quantities.

Cao, S. Y., Chen, J. F., Teng, J. G., Hao, Z., and Chen, J. (2005). “Debonding in RC beams shear-strengthened with complete FRP wraps.” J. Compos. Constr., 9(5).

Ghobarah, A., and El-Amoury, T. (2005). “Seismic rehabilitation of deficient exterior concrete frame joints.” J. Compos. Constr., 9(5).

Hamed, E., and Rabinovitch, O. (2005). “Dynamic behavior of reinforced concrete beams strengthened with composite materials.” J. Compos. Const., 9(5).

Karim, M. R., and Fatt, M. S. H. (2005). “Impact of the Boeing 767 aircraft into the World Trade Center.” J. Eng. Mech., 131(10).

Kent, S. M., Leichti, R. J., Rosowsky, D. V., and Morrell, J. J. (2005). “Effects of decay on the cyclic properties of nailed connections.” J. Mater. Civ. Eng., 17(5).

Ma, T.-W., Yang, H. T., and Chang, C.-C. (2005). “Structural damage diagnosis and assessment under seismic excitations.” J. Eng. Mech., 131(10).

Masmoudi, R., and Zaidi, A. (2005). “Transverse thermal expansion of FRP bars embedded in concrete.” J. Compos. Constr., 9(5).

Masoud, S., Soudki, K., and Topper, T. (2005). “Post-repair fatigue performance of FRP repaired corroded RC beams: Experimental and analytical investigation.” J. Compos. Constr., 9(5).

Muhanna, R. L., Muller, R. L., and Zhang, H. (2005). “Penalty-based solution for the interval finite-element methods.” J. Eng. Mech., 131(10).

Rajabipour, F., Weiss, J., Shane, J. D., Mason, T. O., and Shah, S. P. (2005). “Procedure to interpret electrical conductivity measurements in cover concrete during rewetting.” J. Mater. Civ. Eng., 17(5).

Takewaki, I., and Nakamura, M. (2005). “Stiffness-damping simultaneous identification under limited observation.” J. Eng. Mech., 131(10).

Zhang, X., Zhang, J., Wang, D., and Jiang, J. (2005). “Controlling characteristics of passive mega-sub controlled frame subjected to random windloads.” J. Eng. Mech., 131(10).