Slenderness Limits Research Articles

Geometric analysis and local buckling behavior of wire arc additively manufactured ER110S cruciform section stub columns

The recent prominence and potential of wire arc additive manufacturing (WAAM) in the civil engineering industry have gained significant attention due to its ability to produce complex geometric shapes in a cost-effective and flexible manner. This paper presents the geometric analysis and local buckling behavior of WAAM ER110S cruciform section stub columns. A total of eight specimens with a broad range of width-to-thickness ratios were manufactured. 3D laser-scanning was conducted to capture the geometric characteristics of all the WAAM ER110S cruciform section stub column specimens. Material testing with coupons cut from various orientations of WAAM ER110S plates was performed and this is followed by the stub column testing where digital image correlation (DIC) was employed to monitor the full-field deformations of the specimens. The obtained test data were then employed to assess the applicability of current design rules specified in European, American and Australian standards to WAAM ER110S cruciform section stub columns. The assessment results revealed that (i) the current Class 3 slenderness limits (i.e. slender/non-slender slenderness limits) can be safely used for the classification of outstand plate elements of cruciform sections in compression and (ii) all the three specifications can lead to safe though marginally scattered failure load predictions of WAAM ER110S cruciform section stub columns.

Local buckling behaviour of Q690 high strength steel press-braked elliptical hollow section stub columns: Testing, numerical modelling, and design

This paper presents comprehensive investigations on the local bucking behaviour of Q690 high strength steel (HSS) press-braked elliptical hollow section (EHS) stub columns subject to concentric compression experimentally. In comparison with conventional hot-finished EHS or cold-rolled EHS, the press-braked EHS provides high precision, great construction productivity and the fabricated geometries are not limited to production assembly instrumentation. HSS press-braked EHS fabricated through press-braking process was expected to exhibit distinct behaviour compared with their counterparts constructed from the conventional fabrication routes. Well-understanding of their performance at the levels of material, and cross-section level is essential. Material properties were obtained through tensile coupon tests. Residual stresses in both membrane and bending types were measured and recorded and their impact on structural performance was also assessed. Initial local geometric imperfection measurements were conducted for all the specimens. In conjunction with experimental studies, the finite element (FE) models of Q690 HSS press-braked EHS stub columns were developed. The accuracy of the FE model for HSS press-braked EHS stub column was asserted by comparing the numerical predictions with the tested results. An extensive parametric study was conducted to generate structural performance data with a wider range of cross-section slenderness to complement the test data bank. The cross-section classification for conventional CHS codified in existing standards and the proposed slenderness limits by various researchers were evaluated. The existing slenderness limits cannot be extended to HSS press-braked EHS investigated in this study, a new slenderness limit is proposed. Moreover, the advanced design approaches of Direct Strength Method (DSM) and Continuous Strength Method (CSM) were assessed for their applicability to the cross-section resistance predictions of the examined EHS stub columns.

Prediction of central deflection and slenderness limit for lateral stability of simply supported concrete beam using machine learning techniques

Prediction of central deflection and slenderness limit for lateral stability of simply supported concrete beam using machine learning techniques

Numerical investigation on post–fire resistance of cold–formed Q960 ultra high strength steel channel section stub columns

Numerical analyses on the residual resistant performance of cold–formed Q960 ultra high strength steel (UHSS) channel section stub columns after fire exposure were reported. The proposed numerical modelling method was validated by the existing experimental results of the cold–formed EN 1.4420 austenitic stainless steel, S690 high strength steel (HSS) and S960 UHSS channel section stub columns at room temperature, and the hot-rolled EN 1.4301 austenitic stainless steel channel section stub columns after exposure to fire, where the ultimate resistance, load–end shortening curve and failure mode were considered. The satisfactory comparisons demonstrate the appropriateness of the proposed numerical modelling methodology for the Q960 UHSS channel section stub columns after fire exposure. A parametric study considering different geometric dimensions and exposure temperatures was conducted, where a total of 410 numerical models were included. The geometric dimensions of cold–formed Q960 UHSS channel section stub columns changed the effects of exposure temperature on the load–end shortening curve. For the conditions after exposure temperature less than 600 °C, the slenderness limit of Class 3 in European code could be used for cold–formed Q960 UHSS channel section stub columns. When the exposure temperatures were at 700, 800 and 900 °C, the slenderness limit of Class 3 became unsuitable. The accuracy of design approaches in EN 1993–1-12, AISI S100, AS/NZS 4600 and direct strength method (DSM) was assessed. When the exposure temperatures were at 800 and 900 °C, there were noticeable differences between the numerical results and results obtained from the abovementioned design approaches. The modification methods considering effects of exposure temperature and geometric dimensions were proposed for the EN 1993–1-12 design approach to predict ultimate resistance of the cold–formed Q960 UHSS channel section stub columns after different exposure temperatures.

Numerical and experimental studies on bending behavior of circular aluminium-concrete-steel double skin tubular cross-sections and bending capacity design approach

Considering the excellent corrosion resistance of aluminium alloy, a new-type aluminium-concrete-steel double skin tubular (ACSDST) member is proposed by replacing the outer steel tube of concrete-filled double skin steel tubular members with an aluminium alloy tube to improve structures' corrosion resistance and durability. Until now, no literature has been available on ACSDST cross-section in bending. This paper presents experimental and numerical investigations on the flexural behaviour of circular ACSDST cross-sections in bending. Broad parameters are examined in this research, including varying diameter-to-thickness ratios of the outer tube (20–120), hollow ratio (0.2–0.75), concrete compressive strength (30–70 MPa) and steel yield strength (235–355 MPa). The experimental results show that the final failure is controlled by the tensile rupture of aluminium alloy tubes, but it generally happens after the maximum moment, and the composite section behaves in good curvature ductility. The parametric analysis based on the developed finite element (FE) model discloses the different influences of diameter-to-thickness ratios of the outer tube, hollow ratio, and concrete and steel strengths on the bending moment capacity. Among them, the diameter-to-thickness ratio of the outer tube and hollow ratio significantly affect the bending moment capacity. The design equations for bending moment capacity are induced based on the plastic stress distribution method. Those equations are safe and accurate for the maximum moment (a widely used definition of bending moment capacity) within a certain range of parameters. However, a reduction factor 0.9 is proposed for the equations to predict the moment at a longitudinal flexural tensile strain of 1% (another widely used definition of bending moment capacity). Moreover, the cross-section slenderness limit for the compact ACSDST section is recommended based on the analysis of the experimental and FE results.

Slenderness limit for reinforced ultra-high-performance concrete columns

The use of ultra-high-performance concrete (UHPC) allows for much smaller cross-sections compared to conventional reinforced concrete columns, which may make reinforced UHPC (R-UHPC) columns more susceptible to slenderness effects. Currently, there is no guideline in design standards for the slenderness limit of R-UHPC columns. This paper, therefore, attempts to develop a design provision for determining the slenderness limit of R-UHPC columns. Firstly, a numerical analytical model was proposed for predicting the load-deflection of R-UHPC columns under eccentric loading, which was validated by comparing its predictions with available experimental results from the available literature. Based on the validated model, a parametric study was then conducted to determine the key parameters affecting the slenderness limit of R-UHPC columns. It was found that the slenderness limit corresponding to the 5% strength reduction was sensitive to the ultimate compressive strain of UHPC, the tensile strength of UHPC, and the reinforcement ratio. On this basis, a design equation for the slenderness limit of R-UHPC columns in single curvature was statistically derived. Additionally, the slenderness limit for R-UHPC columns in non-sway frames was also proposed in a convenient form for design procedures.

Design method for cross-section behaviour of hybrid I-girders under uniform bending

Hybrid steel I-girders, characterised by different strength grades for the flange and web, offer the potential to optimise material utilisation in various loading scenarios. The current American and European standards for steel bridges (AASHTO specification and Eurocode 3) have incorporated specific provisions for the design of hybrid I-girders with the web strength grade lower than the flange. Based on the data obtained from the validated numerical investigation, the limiting slenderness ratio for cross-section classification and applicability of the designated bending moment resistance (flexural strength) in standards are assessed. The assessment results reveal that the compact/Class 1 sections with flange yield strength of 690 N/mm2 fail to meet the current codified ductility requirement, and the non-compact flange slenderness limits in AASHTO specification are demonstrated to be excessively lenient. A reduction factor of 1.2 is suggested to narrow down the Class 1 width-to-thickness ratio in Eurocode 3 for I-girders with compression flange steel grade equivalent to S690. Furthermore, the design moment expression of the Direct Strength Method (DSM) is proposed for the cross-section resistance design of hybrid I-girders, and the design approach for the Continuous Strength Method (CSM) is also derived through analytical analysis. Instead of addressing the slenderness of the flange and web individually, the DSM and CSM adopt the concept of overall cross-section slenderness, which allows for a more accurate consideration of the flange-web interaction and offers the potential to streamline the calculation process for cross-section resistance. The statistical and reliability analyses indicate that all the design methods could achieve the reasonable moment resistance predictions for the cross-section resistance of hybrid I-girders.

Inelastic Deformation and Local Slenderness Requirements for Rectangular HSS Braces

Rectangular hollow structural sections (HSS) are commonly used as bracing in concentrically braced frames (CBFs) designed and detailed for seismic design requirements. As the primary yielding component in CBFs, braces are expected to sustain large inelastic axial deformation during earthquake loading. It is well known that their deformation capacity depends on the width-to-thickness ratio (local slenderness). Until 2013, HSS sections were produced to meet ASTM standard A500/A500M; after 2013, the ASTM 1085 specification was implemented, and since that time, HSS sections have also been produced to meet ASTM A1085/A1085M standards. Where the ASTM A500/A500M specification requires minimum yield and tensile stress values as well as a minimum elongation and tolerances on the wall thickness, the ASTM A1085/A1085M specification also requires a minimum Charpy V-notch (CVN) toughness, a maximum yield stress of the steel, and tighter tolerances on the wall thickness and radius of curvature of the corner. These requirements offer a more reliable brace for CBFs in seismic regions. Yet there has been limited research investigating the cyclic axial response of these members. A research study was undertaken to investigate the response of ASTM A1085/A1085M tubes using the response of ASTM A500C tubes as their reference. Forty-one brace specimens were tested under cyclic inelastic axial deformation. Comparison of the data shows that most of the ASTM A500/A500 M Grade C and ASTM A1085/1085M braces meet the respective requirements of their respective ASTM standard and that the differences between the performance of ASTM A500/A500M and ASTM A1085/1085M braces are not dramatic. In addition, the study investigated the impact of width-to-thickness ratio, global slenderness, and displacement history on the response of the braces. The data show that the current AISC 341-22 high-ductility slenderness limit for special concentrically braced frame (SCBF) braces is slightly conservative. However, the data suggest that the moderate ductility slenderness limit used for ordinary concentrically braced frame (OCBF) braces is significantly more conservative than required for consistent seismic safety. Further research is required to determine appropriate limits; this paper provides some initial recommendations based on this dataset.

Flexural capacity and local buckling half-wavelength of high strength steel tubular beams under moment gradients: An experimental study

An experimental investigation into the effect of moment gradients on the flexural behaviour of hot-rolled high strength steel square hollow section (SHS) beams is presented in this paper. In total, 20 beam specimens in steel grades S690 and S770, and with cross-sections spanning from Class 2 to Class 4 based on the Eurocode 3 slenderness limits, were tested under three- and four-point bending. In the three-point bending tests, the beam spans were varied to achieve a range of moment gradients; the influence of different stiffening arrangements at the loading point was also considered. Local geometric imperfections were measured by means of 3D laser-scanning prior to testing and digital image correlation (DIC) was adopted to monitor the displacement and strain fields at critical regions and to assess the local buckling half-wavelengths of the test specimens for which a consistent measurement approach was proposed. The measured local buckling half-wavelengths were compared against the elastic local buckling half-wavelengths calculated using the finite strip method. It was observed that while the measured local buckling half-wavelengths remained approximately constant up to first yield, a significant reduction in half-wavelength was observed with increasing moment due to the non-uniform spread of plasticity. The comparisons also revealed that the local buckling half-wavelengths reduced with both the presence of moment gradients and intermediate stiffeners, with a new parameter proposed to quantify the local moment gradient. It was shown from the tests that the specimens subjected to moment gradients, despite the presence of shear, exhibited higher ultimate moment capacities (up to 10.5% for stiffened specimens and 3.4% for unstiffened specimens) than those subjected to uniform moments. This is attributed to the delay in the local buckling of the critical cross-section of beams under moment gradients due to the restraint provided by the less heavily stressed adjacent cross-sections.

Stiffening of I-section MRF beams against degradation due to local buckling

Moment resisting frame (MRF) beams under cyclic loading are vulnerable to local flange and web buckling. The Seismic Provisions for Structural Steel Buildings (AISC341) prescribe width-to-thickness ratio limits, which are contingent on target rotations during predefined cyclic loadings. Some rolled I-sections available in the market cannot be employed in special MRFs since they fall short of satisfying the AISC341 flange slenderness limit. Moreover, local buckling leads to a decrease in both strength and stiffness in cyclically loaded MRF beams, ultimately increasing the risk of frame side-sway collapse. This paper introduces a stiffening method aimed at improving the behavior of I-section MRF beams. The proposed method involves placing a pair of stiffeners at the plastic hinge regions. A two-phase numerical study was conducted to assess the effectiveness of this approach. In the first phase, nine unstiffened beam cross-sections with varying flange and web slenderness were considered. The slenderness limits specified by AISC341 were evaluated based on cyclic analyses of these beams. In the second phase, a parametric study was conducted on the same cross-sections, with the flange width and the placement of the pair of stiffeners considered as variables. The results revealed a substantial improvement in behavior with the addition of a pair of stiffeners. Cross-sections that failed to meet the flange slenderness limit could be used in MRFs when stiffened. The optimal location for the stiffeners was found to be significantly influenced by the flange width. Design recommendations for the ideal stiffener placement are presented in this paper.

Slenderness limit for GFRP reinforced concrete columns based on axial force ratio

Concrete columns reinforced with fiber-reinforced polymer (FRP) bars have been of great interest in recent years. The distinct properties of FRP bars, such as linear stress–strain behavior and low modulus of elasticity in comparison to steel bars, make the study of FRP reinforced concrete (FRP-RC) columns of importance, especially with regard to the effect of slenderness. This work presents a numerical method for second-order analysis and examines the slenderness limit of glass FRP bars reinforced concrete (GFRP-RC) columns based on two criteria: a reduction in moment capacity at constant load and a reduction in load capacity at constant eccentricity. In the literature, only limited contributions have been made on the slenderness limit of FRP-RC columns, usually based on the latter criterion, whereas there is a lack of literature regarding the slenderness limit of FRP-RC columns based on the former criterion, which is also the slenderness limit criterion of Eurocode 2 (EC2-04) for steel-reinforced concrete (steel-RC) columns. This work may assist in the development of Eurocode provisions, national annexures and guidelines for the design of GFRP-RC concrete columns. A detailed sensitivity analysis was conducted with parameters including the modulus of elasticity of the GFRP bar, percentage of reinforcement, compressive strength of concrete and axial force ratio to examine the variation of slenderness limit for GFRP-RC columns. The axial force ratio is observed to be an important parameter to estimate the slenderness limit from the sensitivity analysis. Variation of slenderness limit for GFRP-RC columns with axial force ratio is observed to be different and the value of slenderness limit is lower compared to the steel-RC columns. Two Equations, which take into account the variation due to the axial force ratio, are proposed to estimate the slenderness limit for GFRP-RC columns.

Behaviour, finite element modelling and design of high strength steel homogeneous and hybrid welded I‐section beams

AbstractThe behaviour and design of homogeneous and hybrid high strength steel (HSS) beams are addressed in the present study. Six in‐plane three‐point bending tests on three different welded I‐sections were first conducted. Following the experimental investigation, a finite element (FE) modelling programme was performed, which included a validation study confirming the accuracy of the developed FE models in replicating the flexural behaviour of HSS welded I‐section beams, and a parametric study generating additional FE data on HSS welded I‐section beams over a broader range of cross‐sectional slendernesses, steel grades and loading configurations. Then, the suitability of the current Eurocode 3 cross‐section slenderness limits for HSS homogeneous and hybrid welded I‐sections in bending were evaluated. It is shown that the current Eurocode Class 2 and Class 3 slenderness limits are suitable for the classification of the outstand flange (in compression) and internal web (in bending) elements of both HSS homogeneous and hybrid welded I‐sections subjected to major axis bending, while stricter Class 1 slenderness limits are considered necessary to achieve sufficient rotation capacity for plastic design. The findings indicate that plastic design can be used for HSS structures, provided the proposed stricter Class 1 slenderness limits are employed. Further work is underway to develop advanced design approaches using second‐order inelastic analysis with strain limits for HSS welded I‐section members.

Strain‐hardening dependent cross‐sectional slenderness limits for the elastic resistance of steel beams

AbstractIt is important that cross‐sections are correctly classified, as this determines their utilisation. The focus of this paper lies on the analysis of the transition point between cross‐sectional classes 3 and 4 for I‐shaped and hollow cross‐sections. In particular, it studies how various degrees of strain hardening and ratios between ultimate and yield strength influence this transition point, which defines whether the elastic moment resistance of a section can be exploited. Numerical simulations with geometrically and materially nonlinear analysis with imperfections (GMNIA) were carried out. The results of the numerical simulations were analysed and consequently, limit slenderness values could be determined and correlations to the hardening behaviour could be found and integrated into corresponding formulas.

Machine learning (ML) based models for predicting the ultimate bending moment resistance of high strength steel welded I-section beam under bending

This paper presents an in-depth numerical investigation into the local buckling behaviour and develops advanced machine learning (ML) -based design methods for high strength steel (HSS) welded I-section beams for predicting the ultimate bending moment resistance under bending. Though HSS welded I-sections are commonly used in construction industry, the interaction effect between the flange and web plates as well as the relatively simplified design formulae result in limited accuracy of ultimate bending moment prediction and complex endeavour is involved for sections subject to local buckling. Finite element models are firstly developed and validated against the collected experimental test data, after which an extensive parametric study is carried out covering a larger range of cross-section slenderness and steel grades. Five ML models including Linear regressor (LR), Support vector regressor (SVR), Artificial neural network (ANN), Random forest regressor (RFR) and Boosting algorithm (XGBoost) were subsequently developed based on the test dataset (experimental and numerical data) to train and test the ML models. Though the current design codes of EN 1993-1-12 and AISC 360-16 can generally provide accurate cross-section classifications with appropriate slenderness limits, the ultimate bending moment resistance predictions are overconservative, particularly for slender sections. The developed ML models outperformed the codified design methods with notable improvements and can be employed in predicting the ultimate bending moment resistance of HSS welded I-section beams under bending.

Practical flexural design approach for one-way hybrid fiber-reinforced concrete slabs based on a parametric study on slenderness limits

Fiber-reinforced concrete (FRC) is increasingly used for structural applications. Slabs are a particularly attractive use for FRC due to a potentially increased redistribution capacity, as well as the efficient cracking control that fibers provide. However, methods for reliably establishing slenderness limits of such elements are missing. Therefore, in this study, a previously developed closed-form solution for slenderness limits of hybrid FRC (HFRC) slabs (steel reinforcement bars and steel fibers) is presented and updated. Subsequently, a comprehensive parametric study on one-way solid slabs is performed, drawing clear conclusions on which parameters are the most influencing and offering a practical flexural design approach in the form of graphs and tables for determining minimum thicknesses of HFRC slabs that may be used as design aids for practitioners.

Design of aluminum alloy channel sections bent about the minor axis

Aluminum alloy extruded channel sections are often used as rafters for light roofs, columns in framed buildings and chords of roof trusses. In this paper, a numerical study is carried out on the response of aluminum alloy channel sections under minor axis bending. Numerical models were developed and validated based on the experimental data of aluminum alloy channel sections under minor-axis bending. Subsequently, parametric studies covering various cross-sectional geometries were performed to expand the numerical data. The results were used to assess the applicability of Eurocode 9 slenderness limits, revealing that the Class 2 and Class 3 limits for outstand flanges under stress gradient with peak compression at tip are too conservative. Moreover, Eurocode 9 underestimates the predicted bending strengths of slender cross-sections due to the lack of consideration of the effect of stress gradient. The equivalent stress gradient factor applied in the effective thickness approach was proposed based on the buckling coefficient of BS 5950. For channel sections bent about minor-axis with the web in compression, flanges exhibit pronounced inelastic behavior even when the web locally buckles. An alternative design method based on the ultimate shape factor of a rectangular plate is proposed for semi-compact and slender channel sections in minor-axis bending (producing compression in the web), which leads to more favorable and less scattered capacity predictions.

Experimental and numerical investigations of S960 ultra-high strength steel welded I-section beams with in-plane flexural failure

A testing and numerical modelling programme was performed to investigate the in-plane flexural behaviour and cross-section bending capacities of S960 ultra-high strength steel welded I-section beams and presented in this paper. The testing programme included material testing, membrane residual stress measurements, initial local geometric imperfection measurements and eight in-plane four-point bending tests, with four performed about each of the cross-section minor and major principal axes. This was followed by the numerical modelling programme, where finite element models were developed and validated against the test results and then used to perform parametric studies to generate further numerical data over a wide variety of cross-section dimensions and span lengths. The obtained test and numerical data were used to evaluate the applicability of the design rules for cross-section classification and bending capacities, as prescribed in the European code, Australian standard and American specification, to S960 ultra-high strength steel welded I-section beams. The evaluation results revealed that all codified slenderness limits were safe (though conservative to different extents) when used for classifying the constituent plate elements of S960 ultra-high strength steel welded I-sections in bending. Moreover, all three considered design codes were shown to result in accurate and consistent bending capacity predictions for Class 1 and 2 (or compact) S960 ultra-high strength steel welded I-sections, but conservative bending capacity predictions, to different extents, for Class 3 (or non-compact) and Class 4 (or slender) S960 ultra-high strength steel welded I-sections.

Optimisation and testing of wire arc additively manufactured steel stub columns

Wire arc additive manufacturing (WAAM), a method of directed energy deposition (DED) for metal 3D printing, is capable of producing intricate parts at a relatively high rate and low cost. Despite the great potential of WAAM for applications in construction, knowledge of the performance of WAAM structural elements is still lacking, and the geometric freedom is yet to be fully harnessed. This study is therefore aimed at investigating the local buckling behaviour of carbon steel WAAM elements and exploring the opportunity for improved structural efficiency through optimisation. An optimisation study was initially conducted to derive optimal stiffener layouts for square hollow sections (SHS) under compression. A total of six plain SHS with a broad range of width-to-thickness ratios, along with two SHS strengthened with optimised stiffeners, were manufactured via WAAM and tested. The six benchmark WAAM SHS profiles were examined to allow direct comparisons with conventionally-produced SHS. 3D laser-scanning was carried out to capture the geometric features of the WAAM specimens, and digital image correlation (DIC) was adopted for the full-field measurement of their structural responses during testing. The WAAM SHS stub columns were shown to have comparable load-carrying capacities to conventionally-produced SHS in the stocky range, but exhibited inferior local buckling behaviour in the slender range. Comparisons with the Eurocode 3 (EC3) resistance predictions showed that the existing Class 3 slenderness limit and effective width method specified in EC3 for plated structures may be overly optimistic for WAAM steel elements owing to their typically larger geometric imperfections. Finally, the SHS strengthened with optimised stiffeners were shown to exhibit significantly improved structural efficiency over both the WAAM and conventionally-manufactured plain SHS, bringing disproportionate increases in load-carrying and deformation capacity relative to the increases in mass.

Strength enhancement and stub-column behavior of cold-formed stainless steel elliptical hollow sections

This paper aims to investigate the strength enhancement, local geometric imperfections, and stub-column behavior of cold-formed (CF) stainless steel elliptical hollow sections (EHS) by using finite element methods. In the present study, an advanced numerical approach was used to conduct a comprehensive parametric study for CF stainless steel EHS with a wide range of cross-section dimensions and slenderness values as well as different stainless steel alloys. By analyzing the generated numerical data from the parametric study, the effects of cold-forming and material parameters on the strength enhancement were examined. Predictive models of the strength enhancement as well as the local geometric imperfections for CF stainless steel EHS are proposed. The slenderness limits for CF stainless steel circular hollow sections (CHS) and CF steel EHS in the existing design methods were assessed for CF stainless steel EHS. New slenderness limits are proposed for CF stainless steel EHS. In addition, the existing equivalent diameter method, the Continuous Strength Method (CSM) and the Direct Strength Method (DSM) were evaluated for the design of CF stainless steel EHS. Modifications on these existing design methods are proposed for CF stainless steel EHS, which can improve their accuracy.

Ultimate behaviour of hybrid stainless steel cross-sections

Hybrid steel plate girders are used worldwide as primary structural members in steel and composite bridges, when there is a need for deeper sections with greater stiffness and bending resistance than rolled sections to carry heavy loads. With the increasing importance of sustainability and lifecycle (cost) analysis, design for maintenance has become an important consideration for infrastructure projects like bridges which have a design working life exceeding 100 years over which they need to be regularly inspected and maintained. Stainless steels are known for their excellent corrosion resistance and low maintenance costs and thus the application of hybrid plate girders in bridge designs could be explored. This paper reports a numerical study on stainless steel hybrid plate girders subjected to compression and to bending and assesses relevant recommendations for their design. Previously developed FE models validated against stub column and four-point bending tests are employed and a parametric study is conducted on hybrid I-sections over a wide range of cross-section slenderness and aspect ratios. Based on the obtained results, the EN 1993-1-4 design predictions for stainless steel cross-sections in compression and in bending are assessed and the accuracy of the codified slenderness limits for both homogeneous and hybrid stainless steel girders is discussed. Furthermore, the numerically obtained deformation capacity at ultimate load is plotted against the CSM base curve originally derived for homogeneous sections and the accuracy of the CSM predictions of the cross-section resistance is also assessed, demonstrating that the CSM can be employed to predict the cross-section resistance of hybrid girders.