Showing papers in "Journal of Structural Engineering-asce in 1988"
TL;DR: In this paper, a stress-strain model for concrete subjected to uniaxial compressive loading and confined by transverse reinforcement is developed for concrete sections with either spiral or circular hoops, or rectangular hoops with or without supplementary cross ties.
Abstract: A stress‐strain model is developed for concrete subjected to uniaxial compressive loading and confined by transverse reinforcement. The concrete section may contain any general type of confining steel: either spiral or circular hoops; or rectangular hoops with or without supplementary cross ties. These cross ties can have either equal or unequal confining stresses along each of the transverse axes. A single equation is used for the stress‐strain equation. The model allows for cyclic loading and includes the effect of strain rate. The influence of various types of confinement is taken into account by defining an effective lateral confining stress, which is dependent on the configuration of the transverse and longitudinal reinforcement. An energy balance approach is used to predict the longitudinal compressive strain in the concrete corresponding to first fracture of the transverse reinforcement by equating the strain energy capacity of the transverse reinforcement to the strain energy stored in the concret...
6,261 citations
TL;DR: In this article, a nearly full-size reinforced concrete columns, of circular, square, or rectangular wall cross section, and containing various arrangements of reinforcement, were loaded concentrically with axial compressive strain rates of up to 0.0167/s.
Abstract: Thirty‐one nearly full‐size reinforced concrete columns, of circular, square, or rectangular wall cross section, and containing various arrangements of reinforcement, were loaded concentrically with axial compressive strain rates of up to 0.0167/s. The circular sections contained longitudinal and spiral reinforcement, the square sections contained longitudinal reinforcement and square and octagonal transverse hoops, and the rectangular wall sections contained longitudinal reinforcement and rectangular hoops with or without supplementary cross ties. The longitudinal stress‐strain behavior of the confined concrete was measured and compared with that predicted by a previously derived stress‐strain model with allows for the effects of various configurations of transverse confining reinforcement, cyclic loading, and strain rate. The measured longitudinal concrete compressive strain when the transverse steel first fractured was also compared with that predicted by equating the strain energy capacity of the tran...
717 citations
TL;DR: In this paper, a nonlocal generalization of the crack band model is proposed, in which the damage that characterizes strain softening is considered to be a function of the spatial average of the positive part of the maximum principal strain.
Abstract: The classical smeared cracking model widely used in finite‐element analysis of concrete and rock cannot describe the size effect experimentally observed in brittle failures and exhibits spurious mesh sensitivity with incorrect convergence to zero energy dissipation at failure. The crack band model circumvents these deficiencies but has limitations with respect to mesh refinement, shear locking on zig‐zag crack bands, and directional bias of the mesh. It is shown that all of these problems can be avoided by a nonlocal generalization, in which the damage that characterizes strain softening is considered to be a function of the spatial average of the positive part of the maximum principal strain. Two alternatives are presented: (1) Smeared cracking whose direction is fixed when cracks start to form; and (2) smeared cracking whose orientation rotates with the maximum principal strain. Furthermore, fracture tests on specimens of various sizes are analyzed by finite elements. It is shown that the model correctl...
204 citations
TL;DR: In this article, the empirical results of a test program studying the effects of rectilinear confinement in highstrength concrete subjected to a monotonically increasing compressive axial load was reported.
Abstract: The empirical results of a test program studying the effects of rectilinear confinement in highstrength concrete subjected to a monotonically increasing compressive axial load was reported. Twentyf...
146 citations
TL;DR: In this article, the authors describe theoretical studies which use bridge measurements to estimate not only the equivalent static loads but also their dynamic variation with time, and the use of measured bending moments gives better results than measured deflections.
Abstract: Earlier impact studies on a small span bridge under service loads gave impact fractions much higher than those specified by AASHTO. This paper represents the first stage of a programme to identify the high impact vehicles. It describes theoretical studies which use bridge measurements to estimate not only the equivalent static loads but also their dynamic variation with time. Acceptable estimates have been obtained. The use of measured bending moments gives better results than measured deflections. The correct selection of nodal spacing and arrangement is important (a).
110 citations
TL;DR: In this paper, a finite element model for brick masonry subjected to in-plane loading is presented, which reproduces the nonlinear characteristics of masonry caused by material nonlinearity and progressive local failure.
Abstract: A finite element model for brick masonry subjected to in-plane loading is presented. The proposed model reproduces the nonlinear characteristics of masonry caused by material nonlinearity and progressive local failure. Bricks and joints are modeled separately, allowing for nonlinear deformation characteristics of the two materials as well as failure of the bricks, the mortar, or the mortar joints by bond. Because of its ability to model local effects, the model is capable of reproducing the behavior of masonry walls in which high local stresses and stress gradients are present (e.g., walls subjected to concentrated loads from beam supports or prestressing anchorages). The material properties for the model are determined from tests on small samples of brickwork and its constituents. Concentrated load tests on brick masonry are used as a basis for comparison between predicted theory and experimental evidence.
102 citations
TL;DR: In this paper, a new formula that represents both ascending and descending portions of uniaxial compressional stress-strain relation is suggested, which implicitly satisfies the basic properties of a complete stress strain relation that the stress ascends, reaches its peak value, and then descends as the strain increases.
Abstract: A new formula that represents both ascending and descending portions of uniaxial compressional stress-strain relation is suggested. This formula consists of two parameters, one governing the steepness of ascending portion and the other controlling the steepness of descending portion. For all possible variations of the parameters, the suggested formula implicitly satisfies the basic properties of a complete stress-strain relation that the stress ascends, reaches its peak value, and then descends, as the strain increases. Expressing the parameters in term of concrete strength, the suggested formula automatically satisfies the behavior of concrete under uniaxial compression that the descending portion becomes steeper as concrete strength is higher. Using the suggested formula, the entire range of strength-stress relation can be favorably determined upon comparing to available test data.
102 citations
TL;DR: In this article, both isotropic and orthotropic reinforcement arrangements were considered and it was concluded that the reinforcement content in a bridge deck can be reduced significantly and satisfy both serviceability and strength requirements.
Abstract: Tests were conducted on 1/6.6‐scale reinforced‐concrete bridge deck slabs under static load, pulsating load applied at a fixed point, and moving constant wheel‐load. Both isotropic and orthotropic reinforcing arrangements were considered. The current AASHTO design approach (orthotropic reinforcement) appears to be overconservative. The moving wheel‐load results in far more damage than the fixed pulsating load, and the cracking pattern due to the former loading is segmental (gridlike) and more extensive. The failure mode for all reinforced model decks is that of punching shear and not flexure. It is concluded that the reinforcement content in a bridge deck can be reduced significantly and satisfy both serviceability and strength requirements.
101 citations
TL;DR: In this paper, it is suggested that to improve resistance to progressive collapse the compression members and diagonal members along and adjacent to the column line should be designed with higher factors of safety than those currently used, particularly in the middle half of the span.
Abstract: Space trusses of the double‐layer grid type, because of their large degree of static indeterminacy, are often assumed to have sufficient redundancy such that the loss of one member would cause force redistributions that can be accommodated by the remaining structure. However, the results presented in this paper of the analyses performed on a hypothetical space truss and on a constructed space truss show that progressive collapse could occur following the loss of one of several potentially critical members when the structures are subject to full service loading. However, when the structures were evaluated using the American National Standard ANSI A58.1‐1982, the structures were found to survive with a small margin of safety. It is suggested that to improve resistance to progressive collapse the compression members and diagonal members along and adjacent to the column line should be designed with higher factors of safety than those currently used, particularly in the middle half of the span. Further researc...
94 citations
TL;DR: In this article, a finite-element method of analysis for elastic flexural-torsional buckling of non-prismatic I•section beam-columns is presented, in which the coupling of torsion and bending is simplified by adopting the web midheight as an arbitrary axis of twist.
Abstract: A finite‐element method of analysis is presented for the elastic flexural‐torsional buckling of non‐prismatic I‐section beam‐columns. The formulation presents a general approach to the problem, in which the coupling of torsion and bending is simplified by adopting the web mid‐height as an arbitrary axis of twist. By making this simplification, the formulation does not sutler from the restrictions of other solutions, such as the use of uniform elements and finite differences. Buckling stiffness and stability matrices are developed, and these may be readily included in existing finite‐element programs. The method is shown to be in good agreement with the more complex finite‐integral treatment, and its scope is demonstrated by application to the buckling of tapered cantilevers.
92 citations
TL;DR: In this paper, a mixed finite element scheme is proposed for reinforced concrete beam columns that exhibits stable numerical behavior even when critical regions become ill-conditioned, and it is demonstrated that enforcing equilibrium within the member during state determination provides the necessary constraint to obtain a stable solution.
Abstract: Finite element models of reinforced concrete beam columns often fail to behave in a stable manner near the point of maximum resistance. Simple numerical examples presented indicate that the conventional displacement formulation when used at the section or member level is unable to establish solutions associated with softening behavior. Thus, such analysis models are often limited in their applicability or necessitate the use of unrealistic material laws. A mixed finite-element scheme is proposed herein that exhibits stable numerical behavior even when critical regions become ill-conditioned. It is demonstrated that enforcing equilibrium within the member during state determination provides the necessary constraint to obtain a stable solution. Examples are presented to demonstrate the reliability and realism of this approach for members subjected to generalized excitations even where severe deformation softening occurs.
TL;DR: In this paper, the results of an experimental investigation into the strength and collapse behaviour of Australian produced cold formed square and rectangular hollow section columns is described and compared with predictions based on the effective width formulae in the American iron and steel institute (aisi) specification.
Abstract: The results of an experimental investigation into the strength and collapse behaviour of Australian produced cold formed square and rectangular hollow section columns is described. The individual plate strengths calculated from the stub column tests on both square and rectangular hollow sections are compared with predictions based on the effective width formulae in the American iron and steel institute (aisi) specification. The long column test results on square hollow sections are compared with the aisi class a and class b column curves as well as a proposal based on the structural stability research council (ssrc) multiple column curves. The sections studied had plate width to thickness ratios in a range where local buckling and yielding occur almost simultaneously, leading to rapid load shedding after ultimate. Theoretical models of the postultimate collapse behaviour, based on local plastic mechanisms, are summarized in the paper. The theoretical models are compared with the collapse behaviour of the stub columns and long columns (a).
TL;DR: In this paper, the authors presented the basic assumptions and theoretical steps leading to the characterization of the equivalent velocity fluctuation through a power spectrum assigned in closed form, allowing one to estimate the dynamic along-wind response of structures, both in frequency and in time domain, with a high level of precision and simplicity; furthermore it makes it possible to treat wind effects, as well as those of earthquakes, through the well-known response spectrum technique.
Abstract: The equivalent wind spectrum technique is a mathematical model according o which wind is schematized as a stochastic stationary Gaussian process made up of a mean-speed profile on which an equivalent turbulent fluctuation, perfectly coherent in space, is superimposed. The equivalent criterion is formulated by defining a fictitious velocity fluctuation, random function of time only, giving rise to power spectra of fluctuating modal force that approximate, optimally, the corresponding modal spectra related to the actual turbulence configuration. This paper presents the basic assumptions and the theoretical steps leading to the characterization of the equivalent velocity fluctuation through a power spectrum assigned in closed form. The method proposed herein allows one to estimate the dynamic along-wind response of structures, both in frequency and in time domain, with a high level of precision and simplicity; furthermore it makes it possible to treat wind effects, as well as those of earthquakes, through the well-known response spectrum technique.
TL;DR: The test results for 21 full-scale concrete block walls subjected to uniformly distributed loading normal to the surfaces of the walls are reported in this article, where simple support conditions on all four boundaries, on the bottom and two sides, on only two sides and on only the top and bottom of the wall are performed.
Abstract: The test results for 21 full‐scale concrete block walls subjected to uniformly distributed loading normal to the surfaces of the walls are reported. The variables included in this experimental study include three wall lengths of 6.0 m (19 ft, 8 in.), 5.2 m (17 ft, 1 in.), and 3.6 m (11 ft, 10 in.) with a constant 2.8 m (9 ft, 2 in.) wall height. In addition, tests were performed with simple support conditions on all four boundaries, on the bottom and two sides, on only the two sides, and on only the top and bottom of the wall. Also, one series of tests was done with precompression loading in the vertical direction. Three repetitions for each combination of parameters were performed to provide a better statistical sample. The test results were compared with both elastic‐plate and yield‐line analyses. In these analyses, the bending strengths used were taken from tests of masonry assemblages constructed to allow testing of individual joints under bending normal to the bed joint and parallel to the bed joint....
TL;DR: In this paper, two approaches are used to derive differential equations, stiffness coefficients, and fixed-end forces for the analysis of structural systems composed of Timoshenko beam-columns that may be supported by an elastic foundation.
Abstract: Two approaches are used to derive differential equations, stiffness coefficients, and fixed‐end forces for the analysis of structural systems composed of Timoshenko beam‐columns that may be supported by an elastic foundation. The analysis is for the evaluation of the critical static axial load and buckling mode‐shapes of a structure with consideration of elastic media, bending, and shear deformations. The two approaches differ in terms of the assumed shear component of the static axial load on the cross section. The first approach is based on the assumption that the shear component of the axial load is calculated from the total slope, which consists of the bending and shear slope. In the second approach, the shear component of the axial load, however, is calculated only from the bending slope. Analytical expressions for a typical simple beam are derived to show the influence of a foundation parameter on the buckling modes. It is observed that the critical axial loads are significantly reduced when shear d...
TL;DR: In this article, a simple constitutive model for nonsmared cracking nonlinear finite element analysis of reinforced concrete structures is described, and the effect of biaxial stress conditions on peak strengths is represented by a variation of the Kupfer-Hilsdorf failure curve in stress space, where the compressive and tensile envelopes are separately specified.
Abstract: A simple constitutive model for ‘smeared cracking’ nonlinear finite element analysis of reinforced concrete structures is described. The model divides the uniaxial response curve for concrete into fivedamage regions, described as linear elastic; compressive strain hardening; compressive strain softening; tensile strain softening; and tensile stiffening regions. Recommendations for incorporating strain localization effects into homogenized material properties in the softening regions are given. The effect of biaxial stress conditions on peak strengths is represented by a variation of the Kupfer‐Hilsdorf failure curve in stress space, in which the compressive and tensile envelopes are separately specified. Recommendations for the effects of tensile cracking and confinement on the shear modulus and the compressivesoftening modulus, respectively, are included. The central thrust of the paper is to incorporate those attributes of the constitutive model which affect the prediction of structural failure modes as...
TL;DR: In this article, the authors investigated the cyclic load behavior of concrete-filled rectangular steel tubular bracing members under quasi-static cyclic loading, and derived the first buckling load for such members based on the observations of test specimens.
Abstract: Cyclic load behavior of concrete-filled rectangular steel tubular bracing members is investigated. Nine full-scale specimens made from A500 Grade B cold-formed steel tubes were tested under quasi-static cyclic loading. The main parameters of the study are: 1) presence of concrete; 2) strength of concrete; 3) effective slenderness ratio; and 4) width-thickness ratio. General cyclic behavior and modes of failure of the specimens are presented. Based on the observations of the behavior of test specimens two procedures are given to compute the first buckling load for such bracing members.
TL;DR: In this paper, the critical load is calculated assuming the configuration of a compressed straight bar with built-in ends, bound on unilateral elastic supports, and a comparison with the results obtained experimentally by other authors makes it possible to assess the reduction coefficient to apply to the theoretical values deduced.
Abstract: The collapse of reinforced concrete structural elements subjected to compression is linked to the instability of the reinforcement bars. This phenomenon may occur in the longitudinal region between two consecutive hoops, or may involve a number of hoops, deforming them through tension until they fail. A criterion is given which makes it possible to determine the unknown length of the region of longitudinal reinforcement involved, in relation to the geometrical and mechanical characteristics of the column. The critical load is then calculated assuming the configuration of a compressed straight bar with built‐in ends, bound on unilateral elastic supports. A comparison with the results obtained experimentally by other authors makes it possible to assess the reduction coefficient to apply to the theoretical values deduced.
TL;DR: In this paper, three sets of real earthquake records are selected to represent seismic ground motions in the low, normal, and high \Ia\N/\Iv\N (peak ground acceleration/peak ground velocity) ranges.
Abstract: Three sets of real earthquake records are selected to represent seismic ground motions in the low, normal, and high \Ia\N/\Iv\N (peak ground acceleration/peak ground velocity) ranges. The inelastic responses of single-degree-of-freedom stiffness degrading systems to the three sets of records are analyzed statistically to investigate the significance of such ground motion characteristics on structural damage. Both damage due to peak inelastic deformation and cumulative fatigue-type damage due to a large number of reversed inelastic deformations are considered. Three damage parameters, each reflecting information on peak inelastic deformation, stiffness deterioration, and hysteretic energy dissipation, respectively, are used to measure structural damage. The mean values of the three damage indicators are obtained for the three sets of accelerograms, and the corresponding dispersion characteristics are examined. It is found that ground motion \Ia\N/\Iv\N range has a significant effect not only on peak inelastic response but also on hysteretic energy dissipation and stiffness deterioration of stiffness degrading systems. The effect on hysteretic energy dissipation is more pronounced than that of peak inelastic response.
TL;DR: In this article, the effects of soil-structure interaction on the dynamic response of linear base-isolated structures are studied and conditions under which the interaction effects are of sufficient importance to warrant consideration in design are defined.
Abstract: A study of the effects of soil-structure interaction on the dynamic response of linear base-isolated structures is presented. The structures are supported at the surface of a homogeneous and viscoelastic half-space and are excited at the foundation. The conditions under which the interaction effects are of sufficient importance to warrant consideration in design are defined. These conditions appear to be different than corresponding conditions for conventional structures, and in particular, the interaction effects in base-isolated structures are not as important as those in conventional structures.
TL;DR: In this paper, a decoupling procedure for finite element computations is applied to the deformation and the rigid body response of a single-degree-of-freedom model, which has been previously shown to compare well with experimental data.
Abstract: A procedure is presented for analyzing underground protective structures subject to conventional weapons effects. A radiation damping term is added to a simple mass-resistance system to include structure-medium interaction effects. This methodology, which is based on a decoupling procedure for finite element computations, is applied to the deformation and the rigid body response of a single–degree-of-freedom model. Numerical examples are given for both applications. The deformation response is shown to be in good agreement with finite element computations that have been previously shown to compare well with experimental data.
TL;DR: In this article, the effective length factor for columns in both braced and unbraced frames is determined directly by the relative joint bending stiffness ratio G's at each end of the column under consideration.
Abstract: The present AISC (American Institute of Steel Construction), ACI (American Concrete Institute), and CAN‐S16.1‐M84 Specifications use alignment charts conveniently to determine effective length factor for columns in both braced and unbraced frames. In this method, the effective length factor K is determined directly by the relative joint bending stiffness ratio G's at each end of the column under consideration. For the development of alignment charts, the far ends of columns above and below the column being designed are assumed to be rigidly connected. In engineering practice, however, some columns may not be rigidly jointed. For an unbraced frame, the present chart always provides an unconservative result when the far end conditions of columns above or below the column being considered are different from the usual alignment chart case. The general equation for the effective length factor K for columns in unbraced frames is derived in the first part of this paper. Extensive numerical studies arecmade using...
TL;DR: In this paper, the hidden safety reserve can be revealed by use of system reliability methods, which can be significantly improved by using of test data to modify the load and resistance parameters.
Abstract: The evaluation of existing bridges has received little attention in the structural reliability literature, yet probabilistic methods allow the evaluation of the adequacy of a structure better than deterministic analysis. Bridge test data can be used to improve the accuracy of load and resistance models. In this paper, available safety analysis procedures are reviewed. Bridge evaluation can be also carried out on the basis of tests, and various bridge test types are discussed. A discrepancy is observed between the analytical and test results. Measured member forces are consistently lower than calculated values. This indicates the importance of load sharing and redundancies. The hidden safety reserve‐can be revealed by use of system reliability methods. The reliability model can be significantly improved by use of test data to modify the load and resistance parameters. The approach is demonstrated on an example of a steel truss bridge.
TL;DR: In this article, statistical techniques are used to combine a first estimate of strength with new information on the past performance of the structure, thereby obtaining an improved estimate of structural resistance, which is then used in the subsequent evaluation of a structure.
Abstract: The successful past performance of an existing structure is evidence of its reliability and safety. A proof load test, for example, provides direct information on strength: the resistance of a surviving structure is shown by the test to be greater than the proof load. Accordingly, the estimate of eliability increases after a successful test. Other kinds of information can be shown to have an effect on reliability similar to proof load testing, including correlation of test and design failure modes, successful resistance to past service loading, and survival age of a structure. In the analyses, statistical techniques are used to combine a first estimate of strength with new information on the past performance of the structure, thereby obtaining an improved estimate of structural resistance. The new estimate of strength is then used in the subsequent evaluation of the structure. Increasing reliability estimates and decreasing failure rates are observed for older structures, and the likelihood of gross error...
TL;DR: In this article, it is shown that the errors in analyzing skew slab-on-girder bridges as right bridges are not characterized by the angle of skew but by two dimensionless parameters, which depend upon the angles of skew, the spacing and span of girders, and their flexural rigidities relative to the flexural rigidity of the deck slab.
Abstract: Those methods of bridge analysis that are developed basically for right bridges are also sometimes used for analyzing (skew bridges provided that the angle of skew is less than 20°. A critical review of this practice is presented in this paper, which also contains a recommended procedure for obtaining longitudinal moments with good accuracy in skew slab‐on‐girder bridges by this practice. It is shown that the errors in analyzing skew slab‐on‐girder bridges as right are not characterized by the angle of skew but by two dimensionless parameters, which depend upon the angle of skew, the spacing and span of girders, and their flexural rigidities relative to the flexural rigidity of the deck slab. Recommendations are given for the use of the simplified methods of analysis for skew slab‐on‐girder bridges. It is proposed that bridges having (S tan ϕ/L) less than 0.05 can be analyzed as equivalent right bridges, where S, L, and ϕ are the girder spacing, bridge span, and angle of skew, respectively.
TL;DR: In this article, a finite difference solution is presented for shear lag effect on the box girders with varying depth, where the spanwise displacement is assumed to be a quartic parabolic curve on the cross section instead of a quadratic.
Abstract: A finite difference solution is presented for shear lag effect on the box girders with varying depth. The analysis is carried out according to Reissner’s method in which the spanwise displacement is assumed to be a quartic parabolic curve on the cross section instead of a quadratic. Under four types of loading, shear lag effects are computed on a cantilever box girder with linearly varying depth. The results are compared with model tests. Finally, some conclusions are drawn about the distribution of shear lag effect along the cantilever box girder with varying depth.
TL;DR: The current American Association of State Highway and Transportation Officials AASHTO methods of lateral load distribution in bridges, because of being too simplistic in basic assumptions, have bee too simplistic as mentioned in this paper.
Abstract: The current American Association of State Highway and Transportation Officials AASHTO methods of lateral load distribution in bridges, because of being too simplistic in basic assumptions, have bee...
TL;DR: The results of a comprehensive study of the seismic response of curved steel box girder bridges are presented in this paper, where the authors used 3D space frame elements and El Centro earthquake accelerogram as a dynamic input to calculate the maximum responses at the bridge deck and columns.
Abstract: The results of a comprehensive study of the seismic response of curved steel box girder bridges are presented. Multiple‐span bridges with up to five spans are analyzed. The bridge is modeled using 3‐D space frame elements and El Centro earthquake accelerogram is used as a dynamic input to calculate the maximum responses at the bridge deck and columns. Different elements of the bridge model and the seismic loading are examined, and a comparison between the response history and the response spectrum methods for analyzing curved bridges, using El Centro earthquake accelerogram, shows that the latter technique fails when vibration modes with relatively high frequencies are considered. The simultaneous application of the earthquake loadings in the three global directions is also discussed. Parametric studies are performed and the effect of the span length, radius of curvature, bridge weight, and column geometry are presented.
TL;DR: In this paper, the authors reviewed selected literature on the subject of errors in structural engineering and found that the majority of structural failures are attributable to errors in design, construction, or operation.
Abstract: The majority of structural failures, whether collapse or functional, are attributable to errors in design, construction, or operation. This paper attempts to review selected literature on the subject of errors in structural engineering. Various features such as the frequency, magnitude, classification, and detection of error are considered, together with causes and environments for error propagation and the role of control strategies in error abatement. In this last respect, the viewpoint on costs largely drives the professional attitude to error. If the full costs fall on the perpetrator, then a lively interest in controls prevails. If the costs are spread among practitioners, then the interest abates and changes to the detection of socially tolerable levels of error and failure incidence. The relation between errors and aspects of professional life and education is also discovered. The significance of frequent personnel changes, compressed design‐construction time, belief in codes and complex calculatio...
TL;DR: In this article, the effects of moment-shear ratio, quantity, and placement of shear connectors, deck orientation, and deck thickness on composite beams with web openings were studied.
Abstract: Fifteen tests to failure are performed on full-scale composite beams with web openings. The beams have ribbed slabs that use formed deck steel. The ribs are perpendicular or parallel to the steel section. The effects of moment-shear ratio, quantity, and placement of shear connectors, deck orientation, and deck thickness are studied. The concrete slab contributes significantly to both the flexural and shear strength of beams at web openings. Peak loads are governed by failure of the slab. Rib failure around shear connectors occurs in slabs with transverse ribs, while longitudinal shear failure occurs in slabs with longitudinal ribs. Strength at an opening increases as the shear-connector capacity above the opening and between the opening and the support increases. The implications for design are discussed.