Eccentric Loading Research Articles

Three-dimensional turning force sensor based on a decagonal ring structure: crosstalk mitigation design and performance optimization

Abstract Real-time data acquisition using high-precision three-dimensional turning force sensors is crucial for intelligent manufacturing. However, existing sensors face challenges such as low integration levels and poor crosstalk resistance, rendering them inadequate for high-precision measurements. Theoretical analysis has demonstrated that a fully centered decagonal ring structure can effectively mitigate the effects of eccentric loading. This study focuses on designing a fully centered turning force sensor with minimal crosstalk. To achieve a balance between sensitivity and stiffness, multi-objective optimization was conducted using GWO-BP and TOP algorithms, resulting in a twofold increase in the sensitivity of the decagonal ring. The sensor design incorporates metallic strain gauges, instrumentation amplifiers, and peripheral circuits into the ring arms of the decagonal structure. Experimental results show that the sensor’s amplified sensitivities in the Fc, Ff, and Fp directions are 11.78 mV N−1, 10.31 mV N−1, and 1.78 mV N−1, respectively. The first three natural frequencies in an unconstrained state are 2518.5 Hz, 2537.5 Hz, and 4256.4 Hz. The sensor’s Fc-Fy crosstalk ranges from 0.18% to 0.88%, with noise limits for the Fc, Ff, and Fp directions of 0.035 N, 0.03 N, and 0.23 N, respectively. Cutting experiments have demonstrated that under varying spindle speeds and cutting depths, the sensor effectively detects surges in cutting force caused by rapid tool retraction, as well as other common faults.

Lateral deflections of slender RC columns under eccentric compression loading with different end conditions

AbstractIn the literature, several methods have focused mostly on determining the lateral deflection of columns with pinned end conditions. This paper presents a powerful method that allows the calculation of lateral deflection for columns of different end conditions, with particular attention to reinforced concrete (RC) columns. By utilizing the moment–curvature relations, a numerical procedure to compute slopes and deflections of pin‐ended columns is proposed, in which the slopes and deflections are corrected via an efficient and fast technique. Accordingly, slopes and deflections of columns with different end conditions are determined via procedures that rely on a simple searching technique. The second‐order analysis is individually included in the calculations; therefore, the complexity arising from the direct impact of the axial load on the lateral deflection is averted. Therefore, the method has the potential for inclusion in many numerical models for different structural members. The equations derived via the developed method have identical responses to the expressions obtained via the exact methods. A series of numerical examples are presented to illustrate the applicability of the proposed method to RC columns with different loadings and end conditions. Finally, the proposed method is evaluated, and its accuracy is demonstrated via parametric verification. As the axial load increased, the lateral displacement increased somewhat. The greater the eccentricity is, the greater the lateral displacement. As the eccentricity increased, the failure mode of the RC column changed from compression failure to bending failure.

Mesoscopic analysis on the coral aggregate reinforced concrete column under axial and eccentric compression

Coral aggregate concrete (CAC) has been identified as a promising building material for reef engineering construction, yet its practical application remains challenging due to incomplete research on the mechanical behaviors of the CAC beam and column components. In this study, a 3D mesoscale modeling approach considering the heterogeneity of CAC was utilized to investigate the mechanical performance of coral aggregate reinforced concrete columns (CARCCs) under axial and eccentric compression. Through numerical delineation of failure processes and damage mechanisms at the mesoscale, comprehensive parametric analysis integrating both numerical simulations and experimental validations were executed to assess the load-bearing capacity of CARCC. Results indicate that the mesoscale model has significant reliability in simulating the deformation and cracking failure behaviors and analyzing the load-displacement relationships of CARCC under axial and eccentric compression loads. When under axial loads, macroscopic cracks in CARCC primarily develop in an oblique manner, precipitating significant concrete spalling and extensive cracking failure along the longitudinal axis. Under eccentric loads, failure advances from crack initiation at load points to abrupt vertical fractures in stressed zones, manifesting a decrement in the load-bearing capacity with escalating eccentricity. Furthermore, the strength grade and reinforcement ratio exert a profound influence on the load-bearing capacity, with disparate impacts under varied loading conditions. It is concluded that reinforcement strategies tailored to specific loading conditions have significant implications for the design and safety of reinforced concrete structures in reef engineering projects.

Application of the Cyclic Strain Accumulation Method on Shallow Foundations under Eccentric Cyclic Loading in Sand

Application of the Cyclic Strain Accumulation Method on Shallow Foundations under Eccentric Cyclic Loading in Sand

Accentuated Eccentric Loading and Alternative Set Structures: A Narrative Review for Potential Synergies in Resistance Training.

Chae, S, McDowell, KW, Baur, ML, Long, SA, Tufano, JJ, and Stone, MH. Accentuated eccentric loading and alternative set structures: A narrative review for potential synergies in resistance training. J Strength Cond Res 38(11): 1987-2000, 2024-As athletes become adapted to training over time, it becomes more difficult to develop their strength and power. In a conventional resistance training strategy, volume or load may be increased to provide novel stimuli to break through a plateau. However, physiological stress markers increase with increased volume or load, which is an innate shortcoming. In that case, practitioners strive to develop unconventional strategies that could increase training stimuli while adjusting fatigue. Two programming tactics, accentuated eccentric loading (AEL) using eccentric overload and alternative set structures (AS) using intraset rests, have been reported to increase training stimuli and alleviate fatigue, respectively. Importantly, when merging AEL and AS in various contexts, the 2 benefits could be accomplished together. Because AEL and AS cause different outcomes, it is important to deal with when and how they may be integrated into periodization. Moreover, prescribing eccentric overload and intraset rests requires logistical considerations that need to be addressed. This review discusses the scientific and practical aspects of AEL and AS to further optimize strength and power adaptations. This review discusses (a) scientific evidence as to which tactic is effective for a certain block, (b) potential practical applications, and (c) related discussions and future research directions.

Dynamic Intelligent Analysis of Single-Column Pier Bridges Considering Vehicle–Bridge Interaction

With its advantages of low engineering cost, minimal space occupancy, and aesthetically pleasing shape, the single-column pier bridge is frequently utilized in urban viaducts and interchange ramps. Due to structural peculiarities, the bridge subjected to eccentric loading, flexural and torsional interaction, and centrifugal force may undergo tipping accidents. To better comprehend the overturning resistance of the bridge, the vibration governing equation of the bridge (idealized as an orthotropic thin plate with point supports in the domain model) is established considering vehicle–bridge interaction. An approximate dynamic analysis formula is subsequently derived via a hybrid method using the grey wolf optimizer. Compared with the outcomes of finite element analysis, the maximal deviation arising from this derived analytical formula is approximately [Formula: see text]% with the greater discrepancy being observed in scenarios featuring minimal support reactions. Compared with the finite element method, the proposed method in this study has higher computational efficiency with precision. This analytical solution is then utilized in the parametric study to scrutinize the influences of span, road surface roughness, and vehicle velocity on a single-column pier bridge under four vehicles. The analysis findings indicate that the proposed approach is reasonably precise, remarkably efficient, and efficacious.

Research the lubrication characteristics on the modified main thrust roller of the slewing bearings

The load capacity and lubrication performance of the slewing bearing are fairly sensitive to edge effects at both ends of the main thrust rollers. Therefore, quantitative investigations of the edge effect at both ends of slewing bearing is practically important. In this study, an elastic fluid lubrication model of the slewing bearing that considered the external load and internal structural parameters is established. A modification function of rollers is included in a finite long-line contact elastic fluid lubrication model to perform the dynamic analysis. The simulated oil film’s thickness and pressure distributions are compared under different working conditions. And the edge effect is eliminated by modifying the rollers’ construction. The results indicate that under the large eccentric load, the speed of the slewing bearing must be decreased to ensure elastic fluid lubrication performance. A genetic algorithm that used to discover the optimal modification length shows the best busbar of the main thrust roller is 12 μm, which could decrease the vibration amplitude of the unmodified roller by 8.13%. This result gives a significant way for slewing bearing’s structural design.

The Influence of Eccentric Muscle Actions on Concentric Muscle Strength: An Exception to the Principle of Specificity?

The principle of specificity suggests that the largest changes in strength occur when training resembles the specific strength test. A one-repetition maximum (1RM) test, which tests the maximal concentric strength, is commonly used as a surrogate for strength adaptation. When separating muscle actions into concentric or eccentric phases, multiple lines of evidence suggest that eccentric muscle actions possess several distinct physiological properties compared with concentric actions. In accordance, there are instances where the increases in 1RM strength test were similar between eccentric-only and concentric-only resistance training. This is at odds with the principle of specificity which suggests that individuals who trained with concentric actions would be expected to have an advantage in that specific task. Although the mechanistic reasons why eccentric-biased training carries over to maximal concentric strength remains to be elucidated, the lack of discernible differences in strength gains with eccentrically-biased training (e.g., eccentric-only and accentuated eccentric training) may imply that the effects of eccentric loading in training are transferable to concentric strength. Our review revisits the role of eccentric loading in enhancing concentric maximal muscle strength. We also speculate on potential physiological factors (i.e., molecular and neural factors) that may differentiate the effects of eccentric and concentric resistance training on the changes in muscle strength. Currently, the majority of the studies investigating the changes in strength have been conducted using isokinetic eccentric training. This is important as there is a viewpoint that the magnitude of chronic adaptations with different modalities of eccentric exercises (i.e., isotonic, isokinetic, and isoinertial training) may also differ from each other. While it has been suggested that eccentric action has a greater transferable capacity for strength adaptations compared to concentric actions, future investigations are warranted to investigate with different modalities of eccentric exercises. There also remains a host of unanswered questions related to the role of eccentric action for maximal concentric strength. For example, future studies may examine whether the eccentric action would be additive when the training is already maximally loaded during the concentric action for increasing concentric maximal strength. We suggested a few different designs that could be used to answer some of these questions in future studies.

Displacement-potential analysis of ply-stresses in a partially guided non-uniform short-column of hybrid laminated composites

Reliable and accurate analysis of local stresses in structural problems of fiber-reinforced laminated composites involving nonuniform geometry is of utmost practical importance, especially when they are subjected to local loads and supports. In this research, a new study of ply stresses in a partially guided, nonuniform, short composite column of hybrid laminates, subjected to an eccentrically distributed loading is conducted using an efficient computational scheme. The analytical modeling of the present mixed-boundary-value problem of laminated structure is realized in terms of a single scalar function of space variables (called as displacement-potential function), which is defined by the displacement components of plane elasticity, and is governed by a single fourth-order partial-differential equation of equilibrium. In this modeling approach, the original three-dimensional symmetric laminated column is reduced to a plane-stress scalar-field problem of an equivalent imaginary lamina in an attempt to obtain the corresponding strain field (global laminate strain), which is then used to determine the stress fields of individual plies through the respective transformed reduced stiffness matrices. A finite-difference based computational scheme is developed to solve the representative nonuniform equivalent lamina in terms of the displacement-potential function, which is however well capable of dealing with different ply materials as well as fiber orientations, together with the associated mixed and changeable physical conditions along the boundaries of the column. A 28-ply balanced hybrid laminate composed of boron-epoxy and glass-epoxy plies with various fiber orientation is considered as the structural material for the present column. The stress fields obtained for individual plies as well as the overall laminate are analyzed in the perspective of a number of practical issues of structural design, which include material hybridization, eccentricity of loading and attachment of partial guides to the column. The design stresses of the nonuniform laminated column are identified to be affected significantly by the material and orientation of fibers as well as the laminate hybridization. An attempt is also made to verify the soundness and accuracy of the present computational scheme through the comparison of the present potential-function solutions with those obtained by the conventional computational method.

Punching shear performance of reinforced concrete slab-to-steel column connections incorporating ECC and UHPECC

Unlike the conventional reinforced concrete (RC) slab-column connection, the punching shear generated at the RC slab-to-steel column connection may lead to brittle punching shear failure due to the small area around the steel column. Moreover, the unexpected moments arising from eccentric loading can also lead to the failure of the slab in punching shear mode. This paper proposes employing high-performance concrete (HPC) to fill the critical punching shear zone to improve the punching shear resistance of RC slabs to steel column joints. Experiments on eight RC slabs to steel column connections are reported. The test parameters under investigation are the type of HPC used to fill the critical punching shear zone, the distance (S) of the HPC zone measured from the flanges of the steel column and loading condition (concentric and eccentric). The types of HPC include engineered cementitious composite (ECC) and ultra-high performance ECC (UHPECC). The experimental results show that the proposed techniques can significantly improve the cracking load, elastic stiffness, energy absorption capacity, ductility, failure modes, and ultimate load of the slab-to-column connections. The ultimate load of the tested connections is increased by as much as 33 %, and 28 % for the slabs subjected to concentric and eccentric loading, respectively. However, the ultimate load and energy absorption capacity of the slab with UHPECC having a S value of 1d, where d is the effective depth are lower than those of the control slab. Three-dimensional nonlinear finite element models are developed to simulate the performance of tested slab-to-column connections and validated by experimental results. The parametric study shows that the n (=S/d) value greater than 3.5 has insignificant effects on the ultimate punching shear capacity of the slab. It is demonstrated that the proposed formulas faithfully estimate the ultimate punching shear capacity of slab-to-column connections constructed with different HPCs under concentric and eccentric loadings.

Load transfer behavior of 3D printed concrete formwork for ribbed slabs under eccentric axial loads

3D printed concrete (3DPC) has primarily been used for non-structural applications, with limited exploration into its potential for structural load-bearing applications. This is mainly due to the layered structure of 3DPC and the lack of compatibility of conventional reinforcement strategies to be integrated within the 3D concrete printing process. The post-tensioning of 3DPC structures presents an effective solution to improve the load-carrying capacity and cracking behavior of 3DPC. However, understanding the load transfer behavior and failure modes of 3DPC structures under a particular post-tensioning configuration are crucial to determine the permissible post-tensioning load for a structure without premature failure and to understand the distribution of stresses within the concrete structure under post-tensioning loads. The current study aims to investigate the load transfer behavior and failure mode of a 30 mm thick 3DPC formwork designed for one-way ribbed slabs when subjected to end-anchorage post-tensioning. For this purpose, a series of mechanical characterization and load transfer experiments were conducted on ribbed 3DPC formwork. The mechanical characterization investigations involved examining the compressive and flexural strength, as well as the elastic modulus of 3DPC, under various loading orientations relative to the print path. In the load transfer experiments, the end anchorage post-tensioning system was simulated by applying the axial load to the specimen via end plates bonded to the specimen. The variable parameters of the load transfer experiments were the boundary conditions, the eccentricity of the axial load from the neutral axis, and the topology of the ribbed 3DPC formwork. A digital image correlation system was used to study the axial and transverse strain evolution during the load transfer experiments. The experimental results showed that, regardless of the eccentricity of the applied load, the ribbed 3DPC formwork specimens exhibited higher axial load capacity when the load was applied near the bottom flange rather than the top flange. This was because of the reduced effective cross-sectional area for compression when the load was positioned near the top flanges, a consequence of the selected formwork topology, where top flanges were discontinuous to allow for pouring of the cast concrete within the formwork.

Mechanical‐performance deterioration of RC segment of shield tunnel under high corrosion degree and the transformation of eccentric‐failure mode

AbstractReinforcement corrosion in shield tunnel segments has an important impact on the structure's bearing capacity and failure mode. Generally, a shield tunnel structure is under small eccentric compression, but if the reinforcement corrosion develops sufficiently, then a transition occurs from small to large eccentric load state, thereby lowering the structural bearing capacity and endangering the safety of tunnel operation. In the study reported here, based on the compressive bending load characteristics of the shield lining structure, corrosion test columns with small eccentric loading were designed to simulate the actual force state of the tunnel lining, and the whole evolution process of their mid‐span strain, ultimate bearing capacity, and cracks under different corrosion degrees was analyzed. With increasing corrosion, the bearing capacity, concrete strain, and depth of the compressive zone of a test column decrease more and more rapidly, and at the maximum corrosion degree of 68.32%, the maximum reduction of bearing capacity is 53.23%. The tests show that the failure mode of a test column with high corrosion degree (≥46.25%) is transformed from small to large eccentric failure. Based on theoretical analysis of the normal section bearing capacity of reinforced concrete flexural members, a theoretical method is proposed for calculating the critical corrosion degree for the tunnel lining structure to transform from small to large eccentric failure. The theoretical calculation method is verified against finite‐element calculations, and the present research results offer theoretical support for the durability design and safety evaluation of shield tunnel lining structures.

Experimental and numerical investigations into torsional-flexural behaviours of railway composite sleepers and bearers

Abstract Fibre-reinforced foamed urethane (FFU) composite sleepers and bearers are safety-critical components installed in complex railway switches and crossings. Not only does they need to provide vertical track support, the composite sleepers and bearers must also endure longitudinal and lateral actions stemming from complex wheel and rail interactions. In reality, the railway bearers at crossing noses are susceptible to coupling torsional-flexural loading. The complex non-linear behaviours have never been investigated numerically nor experimentally. It is thus necessary to comprehend torsional-flexural behaviours of FFU composite sleepers and bearers through finite element and experimental approaches. 3D finite element modelling of FFU composite beams have been established to predict the non-linear coupling behaviours. Three specimens of FFU beams have been prepared for robust experiments under each load case. Our studies exhibit excellent agreement between numerical and experimental results. The ductile failure behaviours (post yield point) have been observed from the experiments. Considerable effects of load eccentricity on the flexure–torsion behaviours of the composite members can also be noted. In addition, the load-eccentricity curves have been identified to portray the non-linear behaviour of the railway components under coupling flexural and torsional loadings. The new insights considering their load–displacement relationships, modes of failure and damage, flexural and torsional interactions are the precursors for railway engineers to design and adopt FFU composite sleepers and bearers in practice where complex wheel/rail interface generally causes coupling torsional and vertical loading conditions.

Blind prediction and post-experimental analysis of RC core wall’s cyclic flexural response using MVLEM-FD

AbstractBlind prediction and post-experimental studies of the flexural cyclic response of a U-shaped core wall, tested at UCLouvain, Belgium, are presented. The tested specimen (referred to as UW1) was modelled using a relatively simple 3D force–displacement-based version of the beam–column multiple-vertical-line-element (MVLEM-FD), developed at the University of Ljubljana (UL), using standard element parameters. The blind prediction accurately identified critical failure points within the specimen. However, the predicted type of failure, attributed to the rupture of longitudinal bars in the boundary region of flanges was somewhat different from that observed in the experiment. These bars were indeed ruptured, but their rupture was preceded by their buckling and the spalling of the surrounding concrete core. Moreover, the predicted force–displacement hysteretic loop exhibited a slight shift compared to experimental observations. Post-experimental studies revealed that this discrepancy was primarily due to the modelling of the loading at the top of the wall rather than the modelling of the wall itself. Specifically, an additional bending moment induced by the eccentricity of the vertical load applied using three actuators, which was overlooked in the blind prediction. Upon correcting the loading, the agreement between the numerical studies and experiment was considerably improved in terms of both the global and local response quantities. Additionally, minor improvements in modelling the boundary regions of the wall’s flanges, considering the relatively large unconfined concrete cover, were introduced, leading to enhanced estimations of near-collapse response.

Influence of Load Eccentricity on Performance and Contact Pressures of Ring Foundations on Geogrid-Reinforced Sand

Influence of Load Eccentricity on Performance and Contact Pressures of Ring Foundations on Geogrid-Reinforced Sand

Impact of Eccentric Loading on the Structural Performance of Reinforced Concrete Pad Footings: An Experimental Study

Setting out of building footings are usually carried out using profile board. This method is usually not accurate in locating the position of columns. Hence, columns that are designed as a concentric columns to their respective footings ends up being columns having eccentricities to the pad footings that supports them. Since the stress distribution under pad footing with concentric column is different from that of pad footing with eccentric column, there is need to study the effect of these eccentricity on the load carrying capacity of the pad footing. In carrying out this work, four pad footings and a typical foundation were used. The pad footings were of sizes 230 mm x 230 mm x 150 mm, with columns of 150 mm x 150 mm cross-section. The first pad footing P1SH was pad footing with short column and zero eccentricity, the second pad footing P2SL was pad footing with slender column and zero eccentricity, the third pad footing P3SL was footing with slender column with 40 mm eccentricity, while the forth pad footing P4SL was footing with slender column with 80 mm eccentricity. The foundation comprises of sand which was contained in a sandbox. The sandbox was made of steel plate of dimensions 0.3 m × 0.3 m × 0.2 m of 4 mm thickness, was used to provide support for the foundation. The foundation was produced by compacting loose sand in three layers with 20 blows per layer in the steel box and with density of about 735 kg/m3. The pad footings were placed on top of the foundation contained in the sandbox, and together were placed on the loading plate of Universal Testing Machine (UTM). Compressive load was applied on each of the pad footings through the columns till failure occurred, using UTM. It was found out that pad footing P1SH have the highest load capacity of 261.25 kN, P2SL pad footing with load capacity of 124.24 kN, P3SL pad footing with load capacity of 39.34 kN, while P4SL pad footing with load capacity of 23.30 kN.

Effect of CFRP strip tie configurations on the behavior of GFRP reinforced concrete columns under different loading conditions

This study presents the results of an experimental program on the behavior of concrete specimens reinforced longitudinally with glass fiber-reinforced polymer (GFRP) bars and transversely with square, square-square, and square-circular (S, SS, and SC) configurations of carbon fiber-reinforced polymer strip (CS) ties under different loading conditions. Nine specimens were tested as columns under concentric and eccentric axial loads and three specimens were tested as beams under four-point bending. The experimental results demonstrated that specimens reinforced with the SC configuration of CS ties exhibited superior load-carrying capacity and deformability compared to specimens reinforced with the S or SS configurations when subjected to concentric and eccentric axial loads. Also, the contribution of GFRP bars in the maximum axial load sustained by specimens under concentric axial load is higher for specimens reinforced with SC configuration of CS ties than for specimens reinforced with S and SS configurations of the CS ties.

Analysis of Power Losses and Experimental Method for Determining Resistance in Electric Elevators

To be able to carry out a high-quality analysis of the operation and design of elevator systems with a driving pulley, it is necessary to determine the size of the losses that occur in the drive mechanism and elevator guide rails. The paper defines an experimental procedure for determining the losses and the efficiency coefficient of elevator facilities depending on the relative load of the cabin in operational conditions. The experiment was carried out on a passenger elevator with a rated load of 320 kg and a lifting height of 28 m. An analysis of the resistance, i.e., the source of power losses in vertical lifting devices, was performed, the most significant of which occur and are especially pronounced in worm gear reducers and on the guiding system of the cabin and counterweight, where the type of guiding elements also has an influence. A particular problem is expressed due to the changing state of the contact surfaces (between the guide rails and the guide shoes) during exploitation and the eccentric loading of the cabin. Also, the paper analysed the obtained measurement results to determine the dependence of the efficiency coefficient of the facility concerning the relative load of the cabin.

Eccentric load capacity of ultra-high strength concrete-filled steel tubular lattice short columns

To explore the behavior of ultra-high strength concrete filled steel tubular (UHSC-FST) lattice short columns under eccentric compressive loads, experimental analyses on four specimens and 276 finite element models using ABAQUS were conducted. The study focused on the effects of steel tube wall thickness, concrete strength, steel tube strength, and load eccentricity on failure modes, load-displacement curves, and ultimate load-bearing capacity. Results showed that for columns with minor eccentricity-induced compressive failure, the reduction coefficient of ultimate load capacity has a weak correlation with the parameters. However, for columns with significant eccentricity-induced tensile failure, the reduction coefficient increases with steel tube thickness and strength and decreases with concrete strength. The center-to-center distance of the columns has a minor effect. Based on these findings, a comparative analysis of existing standards was conducted, leading to the development of an accurate method for calculating the ultimate load-bearing capacity of eccentric CFST lattice columns. This method is applicable to various cross-sectional dimensions, material strengths, and steel tube wall thicknesses, with calculation errors within 10 %, ensuring it meets engineering precision requirements.

Eccentric compression behavior of CFRP-confined reactive powder concrete-filled steel tube slender columns

Ultra high and large-span structural components are needed in urban modernization construction to meet the engineering requirements. Reactive powder concrete-filled steel tubes (RPCFSTs) provide a cost-effective and efficient solution for optimizing space utilization in super high-rise buildings and enhancing the crossing capacity of bridge, which accords with such development. However, these components have inherent drawbacks in terms of local buckling and corrosion resistance. The use of carbon fiber reinforced polymer (CFRP) confinement to suppress this innate deficiency has been proven to show great advantages in limited trial results. This article establishes a comprehensive test scheme to investigate the eccentric compression performance of CFRP-confined RPCFST columns. A total of 11 specimens were prepared and subjected to biased compression test by varying the component length (400, 800, 1200, and 1600 mm), number of CFRP layers (0–3), and load eccentricity (0, 10, 20, 30, and 40 mm). The results showed that the CFRP confinement could effectively enhance the bearing capacity and energy dissipation capability of RPCFST columns while delaying the local buckling of slender specimens with low slenderness ratios. The improvement of ultimate load due to CFRP confinement exceeded 42.5 %. However, in specimens with higher slenderness ratios and with increasing load eccentricity, the confinement effect of the steel tube on the core RPC tended to weaken. An N–M interaction model for slender CFRP-confined RPCFST columns was established, and this model was validated to be in good agreement with the experimental results. The conclusions drawn from this study might given a solid foundation for the future application of CFRP-confined RPCFST structures.