Abstract:Corrosion is a major durability problem for steel structures, and atmospheric corrosion is the most common corrosion that causes the greatest loss. Over the years, researchers have studied the atmospheric corrosion process of various kinds of steel through in-situ test of in-service steel structures, atmospheric exposure test, accelerated corrosion test, electrochemical test, and other methods. The corrosion mechanism of steel in different environments were analyzed and corrosion models were put forward. In this paper, the research status and progress of atmospheric corrosion models of structural steel are discussed from three aspects: corrosion mechanism of steel in typical corrosive atmosphere, time-dependent model of corrosion loss of steel, and pitting depth development and distribution of steel surface.

Abstract:In the low-cycle reciprocating loading test of cold-formed thin-walled steel composite wall connected with rivet locking or self-tapping screw, the phenomenon of “pinching” of hysteresis curve is serious and the energy dissipation capacity is poor. To reduce the damage of cold-formed thin-wall steel composite wall under earthquake and improve the energy dissipation capacity of the structure, a cold-formed thin-wall steel composite wall structure system with lead damper was proposed, and seismic performance experimental study was conducted based on three variables, i.e., cold-formed thin-walled steel composite wall corner connection mode, panel rivet spacing, and type. Results show that with the addition of the lead damper, the deformation capacity and energy dissipation capacity of the cold-formed thin-walled steel composite wall structure system based on rivet locking or self-tapping screw connection were significantly improved under the low-cycle reciprocating loading. The stiffness degradation tended to be gentle, the injury index was significantly decreased, and the failure pattern was optimized, while the yield load and peak load were slightly reduced. Then, with the rivet spacing reduced, the yield load, peak load, peak displacement, and shear strength of the composite wall were improved to some extent, but the energy dissipation coefficient had little difference. Meanwhile, the yield displacement, yield load, peak displacement, and peak load of the cold-formed thin-walled steel composite wall based on rivet connection were significantly higher than those of the cold-formed thin-walled steel composite wall based on self-tapping screw connection, but the ductility and energy dissipation coefficient of the walls were similar.

Abstract:Based on the advantages of concrete filled steel tube (CFST) column and reinforced concrete (RC) beam, a new type of CFST column-RC beam joint connected by U-shaped steel plate and studs is proposed in this paper. In order to study the seismic performance of the new type of joint, two full-scale CFST column-RC beam joints and one traditional RC joint were designed and manufactured, and the low-cycle reciprocating load test was carried out. Results show that the failure mode of the CFST column-RC beam joint was similar to that of the traditional RC joint that both of the joints had flexural failure at beam ends. The failure area was mainly outside the U-shaped steel plate edge, and the plastic hinge area moved outwards. The beams of the cross joint were named as S beam and N beam according to the specimen installation positions of the test site. Compared with the RC joint, the bearing capacity of the N beam of CFST column interior joint and side joint increased by 11.6% (13.0% in negative direction) and 5.3% (7.5% in negative direction) respectively, and that of the S beam of the CFST column interior joint increased by 20.2% (19.6% in negative direction). The load-displacement hysteresis curves showed a plump shape. The accumulative energy dissipation of the CFST column interior joint and side joint increased by 17.0% (36.0% for S beam) and 20.1% compared with the RC joint. The displacement ductility coefficient of each specimen was higher than 4.0, and that of the interior joint and side joint of the CFST column-RC beam increased by 2.4% and 21.3%. Therefore, the new type of CFST column-RC beam joint showed good deformation ability.

Abstract:In order to study the influence of different column foot connections exerting on seismic behavior of single story and single span self-centering steel beam with I beam, two types of self-centering steel frame specimens composed of fixed column foot and articulated column foot respectively were designed and manufactured. The load transfer mechanism, bearing capacity, hysteretic behavior, ductility, energy dissipation capacity, and self-centering capacity of the specimens were analyzed by low cyclic loading test. Test results indicate that the self-centering frame with fixed column foot had larger residual deformation and poorer self-centering effect, since the required restoring force of the column foot after yielding was much greater than the force provided by the self-centering I beam. Therefore, it is not recommended to be adopted as column foot connection for such structures. The load transfer mechanism of the self-centering frame with articulated column foot agreed well with the theoretical analysis results. Only energy dissipation fuses had plastic deformation, and the residual deformation was small after unloading, indicating that it has the characteristic of “resilient structure”. When story drift was loaded to 4%, the skeleton curve had no descending section, and the self-centering frame with articulated column foot had adequate capacity reserve. The displacement ductility coefficient of the specimen was 3.1, and the equivalent viscous damping coefficient was 0.19, which shows that the structure has good seismic behavior.

Abstract:The seismic design of marine structures so far still relies on civil engineering design codes. The objective of this study was to point out the importance of using offshore ground motion for seismic design and safety assessment of marine engineering. Several earthquakes in history were selected, and the focus was on paired offshore and onshore accelerations with identical epicenter distances. Three key elements of seismic motions were discussed, and Hilbert-Huang spectrum was adopted to distinguish energy distributions in terms of temporal and spectral characteristics. Results show that the peak ground acceleration of offshore horizontal motion was larger than that of onshore horizontal motion. The duration was generally longer, and the response spectrum shifted to moderate and low frequencies. These features may have unfavorable effects on structural dynamic response. As revealed by the Hilbert-Huang spectral analysis, the frequency corresponding to the main energy of offshore ground motion was lower than that of onshore ground motion, and the frequency corresponding to the largest instantaneous energy was almost identical to peak-to-trough frequency rather than predominant frequency in Fourier spectrum.

Abstract:To study the effect of three limit states (force limit state, displacement limit state, and compound limit state) of a liquid viscous damper on the seismic response of single-degree-of-freedom (SDOF) systems, the three limit states of the viscous damper were simulated, and a reliable numerical analysis model was obtained by Ruaumoko-2D. Then, the reinforced concrete structures of two and ten storeys were modelled into two equivalent SDOF systems, each of which was connected in parallel with a viscous damper. Time history analyses under the increasing action of multiple seismic waves and sine waves were conducted respectively to investigate the influence of the force limit state, displacement limit state, and compound limit state of the viscous damper on the SDOF system response. By comparing with the SDOF systems without considering limit states, the variation of the displacement ratio with the peak speed of the ground motion was obtained.

Abstract:To improve the stability of steel desulfurization tower, the anti-collapse mechanism of bamboo structure was clarified considering the relationship between structural characteristics and mechanical behavior, and it was applied to the imitation bamboo design of steel desulfurization tower structures. The seismic performance of bamboo-like desulfurization tower was analyzed by scale model shaking table tests. Based on the principle of stiffness gradual change, a design method of sectional variable wall thickness for desulfurization tower was proposed to ensure that the changing trend of section stiffness of bamboo-like desulfurization tower was consistent with that of the bamboo body. Stiffener setting was discussed through the eigenvalue buckling method. Stiffener could improve the buckling mode of the structure distinctly, and it is reasonable to set the stiffener spacing of 4 m as the base number. Test results show that the maximum displacement and stress of the structure did not exceed the allowable value under the action of 7 or 8-degree earthquake. The structure was in an elastic state without damage. Under the action of 9-degree earthquake, the maximum stress of the tower exceeded the material allowable stress at working temperature, and local mild bending occurred on the tower, but the structure still did not collapse.

Abstract:Influenced by the wake flow of upstream cylinder, the downstream cylinder is prone to wake-induced vibration at small wind angles. Although fluctuating lift is closely related to wake-induced vibration, the characteristics of fluctuating lift are less investigated, and the flow field mechanisms are not yet clear. For two staggered circular cylinders with center-to-center pitch ratio P/D of 1.5-4, by using the large eddy simulation (LES) method, the intrinsic relationships between the fluctuating lift of the cylinders and the flow fields were studied at small wind angles (β=0°-30°) with a high Reynolds number of Re=1.4×10⁵. The interference mechanisms between the two cylinders were explored based on the flow field mechanics. Results show that the fluctuating lift of the cylinders and the flow field mechanisms experienced significant changes at small wind angles, and there were five different interference flow patterns, namely, wake interference, shear layer interference, proximity interference, interaction between vortex and cylinder, and interaction between vortex and vortex. Under wake interference and shear layer interference, the fluctuating lift of the downstream cylinder was much smaller than that of a single cylinder. Under proximity interference, the interaction between the two cylinders was weak, and the fluctuating lift of the downstream cylinder was close to that of a single cylinder. For the interaction between vortex and cylinder and the interaction between vortex and vortex, the fluctuating lift of the downstream cylinder was higher than that of a single cylinder, and the wake vortex impinging of the upstream cylinder on the downstream cylinder or the interaction with the downstream cylinder led to the rapid increase of the fluctuating lift of the downstream cylinder.

Abstract:Electrochemical rehabilitation technology is an effective method to improve the durability of chloride ion contaminated concrete structures. However, negative effects such as reduction of bonding performance, pore structure changes of concrete, and hydrogen embrittlement of steel bar are induced simultaneously, leading to the service performance deterioration of the monolithic component. In order to explore the durability enhancement and mechanical properties of concrete beams after electrochemical chloride extraction and bidirectional electromigration, the corrosion resistance properties of concrete beam after electrochemical rehabilitation were analyzed by combining chloride ion content gradient and potentiodynamic polarization curves, and the static mechanical properties were investigated through load-deflection curves, strain of steel and concrete, and crack distribution of concrete. Results show that electrochemical rehabilitation could effectively remove the surface chloride ions of steel bar and restore the passivation of steel bar, but the extraction of the chloride ions inside steel cage was difficult. When small electrification parameters were selected, electrochemical rehabilitation hardly affected the stiffness and load bearing capacity of the beam, while the bearing capacity decreased when the amount of electricity increased, and the ductility degradation became more obvious. In order to meet the requirements of durability and structural safety, it is suggested that effects of durability enhancement and impacts on mechanical properties deterioration should be comprehensively taken into consideration when selecting electrification parameters for electrochemical rehabilitation.

Abstract:To investigate the load transferring mechanism of different corner fitting joints under horizontal static load, horizontal static load tests of full-scale frames with four types of corner fitting joints (shaped of L, T, cross, and grouting L) were designed based on the double-layer single span structure of a proposed new assembled composite light-weight slab structure residential project. The working performance and failure characteristics of the steel frames with different joints were studied, and the results were compared with ABAQUS numerical simulations. According to the results of tests and numerical simulations, the initial stiffness and ultimate bearing capacity of the frames, as well as the strain values at different cross sections were obtained. Results show that the corner fitting joints of the new light-weight slab structure worked well, the steel frames broke in the beam hinges, and the joints were intact, which fulfilled the design requirements of "strong column and weak beam" and "strong joint and weak member". The double columns of T shaped joint had a good cooperative performance, and the columns of L and cross shaped joints were prone to deformation. Small diagonal braces and grouting joints increased the initial stiffness of the steel frames by 38% and 14% respectively. The double beams worked independently, and the multiple columns worked incompletely independently. A calculation method for equivalent bending stiffness of double-beam and multi-column was proposed through strain analysis. Numerical simulations agreed well with the tests results, which verified the correctness of the conclusions.

Abstract:The influence of existing cracks on acoustic emission (AE) wave propagation characteristics is not taken into account when using AE technology to locate cracks or detect damages in concrete structures, which often leads to large deviations in detection results. To explore the influence of crack parameters on the velocity and amplitude attenuation of AE wave in reinforced concrete (RC) slabs, four-point static loading test and AE test were carried out on three RC specimens with different protective layer thicknesses, and the influences of crack depth, crack width, and crack amount on the propagation properties of AE wave were analyzed. Tests and analysis results show that crack width and crack amount both had little effect on the velocity and amplitude attenuation of AE wave, while crack depth had significant effect. With the increase of the crack depth, the amplitude attenuation increased, and the velocity decreased. Then, a time-of-arrival location method based on variable velocity was proposed considering the effects of cracks, which was compared with traditional method in detecting crack locations. Results indicate that the proposed method had higher accuracy in detecting crack locations in RC structures.

Abstract:To improve the accuracy of the classic Vlasov torsional theory when it is applied to analyze deep beams with open cross sections, restrained torsional calculation formula was derived based on the effect of shear deformation and the Vlasov torsional theory. Equilibrium differential equations were obtained in consideration of the influence of shear deformation, and the solutions were obtained through initial parameter method. Then, U-shaped RC beams (span of 6.65 m and 3.325 m) were calculated by the proposed calculation method, Vlasov torsional theory, and ABAQUS simulations. It was found that results of the two calculation methods were close to each other for the long U-shaped beam with large span-height ratio (when l/h＞10, the variation was within 20%), which was consistent with the experimental and simulation results. However, for the short U-shaped beam with small span-height ratio, the torsional rotation was significantly underestimated by the Vlasov torsional theory (when l/h＜6, the variation exceeded 40%), while the results obtained from the proposed method well coincided with the experimental and simulation results. Therefore, the method proposed in this paper could overcome the limitation of ignoring shear deformation in the classic Vlasov torsional theory, which is suitable for the calculation of torsional deformation of open thin-walled members with both large and small span-height ratios.

Abstract:To study the effect of the stiffening plates between brace and chord and the width ratio of brace section to chord section on failure mode, bearing capacity, and distribution and evolution of stress and strain in connection zone of T-joints of lightweight aggregate (LWA) concrete-filled high strength steel square tube truss, static loading tests under axial compression on brace were performed on T-joint with stiffening plates and traditional T-joint. Tests results show that typical failure modes of T-joints of LWA concrete-filled high strength steel square tube truss included concave of top flange of chord in connection zone, convex of chord webs, bending of chord, lateral instability of brace, buckling of stiffening plates, crack of weld between chord and brace, and crack of weld between stiffening plates and brace. The bearing capacity of the traditional T-joint depended on the compressive strength of brace root and its welds and the local compression zone of top flange of chord in connection zone, and there was a flow-plastic platform in the load-displacement curve of the traditional T-joint. The bearing capacity of the stiffened T-joints depended on the compressive strength of brace root and its welds, the diffusion compression zone of top flange of chord in connection zone, and the buckling strength of stiffening plate. The load-displacement curves of the stiffened T-joint showed gradual upward trend without flow-plastic platform. The bearing capacity of the T-joints was obviously improved by the stiffening plates. The yield load and ultimate bearing capacity of the stiffened joints increased by 10.0%-40.0% and 15.0%-48.3% compared with those of the traditional T-joint, respectively. The yield load and ultimate bearing capacity of the stiffened joints increased with the increase of the width ratio of brace section to chord section.

Abstract:To study the size effect of reinforced concrete columns strengthened with carbon fiber reinforced polymer (CFRP) under axial compression loading, three groups of thirty geometrically similar reinforced concrete columns strengthened with CFRP were designed and tested. Test parameters including column size, reinforcement layout, and loading history were studied, and the relationships between the properties of the proposed columns (such as failure mode, ultimate strength, peak stress, and residual deformation) and column size were investigated under axial compression loading. Experimental results show that with the same size, the ultimate strength of the reinforced concrete columns strengthened with CFRP was higher than that of the plain concrete columns. As the size of the concrete columns strengthened with CFRP increased, the peak stress first increased and then decreased. The normalized axial deformability and residual deformation of the concrete columns strengthened with CFRP decreased with the increase in the size of the columns. Different loading histories had little effect on the bearing capacity and ultimate displacement of the concrete columns strengthened with CFRP.

Abstract:To study the bond performance between internal steel and concrete in concrete filled steel tube (CFST), 18 CFST push-out tests were conducted. The bond mechanism and bond stress distribution law between two kinds of internal steel and concrete were studied. The influencing law of parameters on bond strength was obtained and analyzed through orthogonal test, and empirical formulas of bond strength were proposed based on measured data. Test results show that bond stress-slip curves of both internal I-shaped steel and internal steel tube consisted of 3 stages, namely, adhesive stage, non-liner initial sliding stage, and sliding stage. For internal I-shaped steel, the parameters that influenced ultimate bond strength were in order of section size of internal I-shaped steel, bond length, and concrete strength in terms of importance. The ultimate bond strength of the internal I-shaped steel increased with increasing section size of I-shaped steel and concrete strength, while decreased with increasing bond length. For internal steel tube, the parameters that influenced ultimate bond strength were in order of section size of internal steel tube, mixing amount of expansion agent, and bond length in terms of importance. The ultimate bond strength of the internal steel tube increased with increasing section size of internal steel tube and mixing amount of expansion agent, but decreased with increasing bond length. Bond stress distributions of both internal I-shaped steel and internal steel tube exhibited negative exponential relations under peak load, and the average bond stress on external flange of I-shaped steel was about 1.77 times that of web. The bond performance between internal steel tube and concrete in CFST was better than that of internal I-shaped steel. A comparison with previous research results verified the better applicability of the proposed formulas.

Abstract:To transform the swimming pool of the National Aquatics Center into a curling field for the 2022 Winter Olympics, a construction method of a fully assembled curling field with supporting structure was proposed in consideration of a new ice-making method. Based on the results of field test and finite element analysis conducted on the assembled ice rink, the characteristics of the natural frequencies and corresponding mode shapes of the assembled ice rink were studied. The overall deformation and the stress level of each component of the ice rink under service loads were analyzed, and the stress, deformation, and cracking in ice layer under extreme loads were discussed emphatically. The research shows that the proposed assembled ice rink had greater stiffness and loading capacity, which can meet the requirements of curling games in Winter Olympics. This kind of ice rink should be operated by a light ice resurfacing machine, since ice cracking is likely to be generated under bending and shearing actions of wheel load of large ice resurfacing machines.

Abstract:To investigate the difference of mechanical properties between sleeve grouting butt joints and lap joints, 24 butt joints and 12 lap joints were tested under unidirectional tension. The failure modes, bearing loading capacity, ductility, force-displacement curves, and sleeve strain of the joints were compared and studied. During the loading process, the grouting material of the butt joints cracked in full section at the middle of the sleeve, and was pulled out of the sleeve at the end of the loading process, while the lap joint had no such situation. Test results show that the bearing loading capacity, total elongation, and stiffness of lap joint were 5-7 times, 3-5 times, and 2-3 times larger than those of butt joint respectively when the sleeve length was the same, and the displacement ductility coefficient was larger than that of butt joint. When the anchorage length was the same, the bearing capacity and displacement ductility of lap joint were slightly larger than those of butt joint. The initial stiffness difference between the joints was not obvious, but the mid-late stiffness of lap joint was higher than that of butt joint. When the middle section of the butt joint sleeve was longitudinally tensioned, the lap joint was tensioned in the early stage of loading and compressed in the late stage of loading, which reflects the lower requirement of the tensile strength of the lap joint sleeve. When the middle section of the butt joint sleeve was circumferentially compressed, the lap joint was compressed in the early stage of loading and tensioned in the late stage of loading, indicating that the restraint effect of the middle part of lap joint sleeve on the grouting material was greater than that of butt joint. The mechanical property of lap joint is better than that of butt joint, so it can be used to connect reinforcement bars in prefabricated assembly structures.

Abstract:Soda residue is the solid waste generated during the ammonia-soda process for soda ash, while there is no effective treatment and utilization disposal method. In order to maximize residue utilization, soda residue, blast furnace slag, steel slag, and desulfurization gypsum were used as composite cementitious material, and iron tailing sand and waste rock were used as aggregate to prepare clinker-free concrete. Results show that by mixing 30% soda residue, 45% blast furnace slag, 15% steel slag, and 10% desulfurization gypsum, the 28-day compressive strength of the clinker-free concrete could reach up to 38.33 MPa. Hydration products and hydration process of the composite cementitious material were studied through XRD, SEM-EDS, TG-DSC, and IR, and results show that the hydration products of the composite cementitious material were mainly C-S-H gel, ettringite (AFt), and Friedel’s salt (FS). The synergistic reaction mechanism between the raw materials was analyzed to further understand the formation process of the hydration products. Moreover, durability analysis of all-solid waste concrete demonstrates that the concrete had good frost and carbonation resistance, while its dry shrinkage resistance and sulfate attack resistance were poor. Finally, the preparation conditions, application scope, and application prospects of the soda residue clinker-free concrete were analyzed, which provides an in-depth scientific basis for the harmless and resource utilization of soda residue.

Abstract:To explore the tensile properties of glass fiber reinforced polymer (GFRP) bars exposed to different aggressive environments, the tensile properties of GFRP bars before and after conditioned were tested. Effects of environmental categories and exposure periods on the tensile properties of GFRP bars were analyzed. The GFRP bars were conditioned in two different ways: the first part of GFRP bars were directly immersed in different solutions (alkaline solution, salt solution, and tap water) with the immersion period of 180 days; and the second part of GFRP bars were embedded in sustained-loaded concrete beams exposed to outdoor air and NaCl solution in drying-wetting cycles with the total period of 366 days. Scanning electron microscopy (SEM) was used to analyze the microstructure changes of the GFRP bars placed in concrete beams. Test and analytical results show that the tensile properties of the GFRP bars immersed in aggressive solutions had different degrees of degradation with increasing exposure period. After 180 days of exposure to solutions, the tensile strength decreased by 30.0%, 21.3%, and 11.3% in alkaline solution, salt solution, and tap water, respectively. For the GFRP bars embedded in concrete, the average loss of the tensile strength of the bars was about 10% after 366 days. Based on the test results and SEM microstructure analysis, it can be deduced that the main reason of the degradation of conditioned GFRP bars is the debonding between the fibers and the resin matrix. Finally, the tensile strength degradation of GFRP bars under two conditions were fitted based on Arrhenius model. In addition, the long-term performance predictions of GFRP bars exposed to alkaline solution and salt solution and embedded in concrete beams were proposed, respectively.

Abstract:Subway concrete is easy to be attacked by aggressive CO₂ in underground space, and alkali aggregate reaction (AAR) is a severe durability problem which is difficult to find and repair. Durability decrease of subway concrete caused by these two problems seriously affects the normal use of the subway tunnel. To investigate the impact of nano-particles on the durability of subway concrete under the combined action of aggressive CO₂ and AAR, two kinds of nano-particles (nano-SiO₂ and nano-Fe₂O₃) were respectively mixed into plain concrete to prepare concrete with nano-particles. Durability test was carried out by using a self-developed equipment, and erosion depth, expansion, and sonic velocity were selected as indices to evaluate the durability of the concrete with nano-particles under the combined action of aggressive CO₂ and AAR. Test results show that after mixed with nano-particles, the erosion depth and expansion of the concrete were decreased obviously, while the sonic velocity was increased significantly, which demonstrates that the durability of the concrete with nano-particles was better than that of plain concrete. At the age of 182 d, the concrete with 2% of nano-SiO₂ showed the best durability performance that the erosion depth and expansion were the smallest and the sonic velocity was the largest with least decrease, followed by the concrete with 1% of nano-Fe₂O₃. The enhancement of durability was due to the special physical and chemical properties of the nano-particles which improved the microstructure of the concrete and the chemical composition in pore solution.

Abstract:To study the influence of stressed skin on the global stability of aluminum alloy frame of radome structure, a static loading test was conducted on a radome which has a span of 5.8 m and a height of 4.3 m. A self-designed multi-stage distribution beam loading system was applied to the structure, and simultaneous multi-stage loading was realized on the structure at multiple points. Three load cases, i.e., completely covering skins, partially covering skins, and framework, were discussed respectively. Test results show that due to the lateral bracing of the stressed skin on the aluminum alloy members, the prematurely elastic instability of the members around the weak axis was avoided, which significantly improved the global stability bearing capacity of the structure. When a small amount of stressed skin was destroyed, the global stability bearing capacity was still much higher than that for the framework case. Therefore, in the design of such radomes, the cooperative performance of the stressed skin and the frame should be considered to solve the problems of structural safety and electromagnetic transparency.

Abstract:To explore the mechanical performance of aluminum alloy hub joints in spatial structure system, nonlinear finite element software ABAQUS is used to establish refined numerical models for 25 aluminum alloy hub joints with different sizes to study the tensile and compressive properties. The effects of hub body groove spacing, tooth spacing, tooth width, tooth depth, and other factors on the mechanical performance of the nodes are studied. Results show that the tensile bearing capacity of the joint is mainly borne by the concave and convex grooves between the hub body and the embedded part of the rod. When the parameters are changed, there are four failure modes in the tensile limit state: hub body convex tooth flexural shear failure, hub body innermost groove flexural shear failure, hub body outermost groove flexural shear failure, and hub body convex tooth shear failure. Within the range of study, if the hub body groove spacing and tooth width are increased, the tensile ultimate bearing capacity of the nodes increase by 71.3% and 112.9% respectively. The stress of joints is mainly caused by instability, and the change of parameters have little effect on the pressure of joints. Finally, the formula of ultimate bearing capacity and the design suggestion are given.

Abstract:To study the bearing capacity of high strength bolt connection for longitudinal seam of corrugated steel plates (CSPs), finite element models of test specimens were established by ABAQUS software. Influences of end distance, bolt preloading, and waveform of high strength bolt on the bearing capacity of CSP connection were discussed. Results show that the end distance of CSP connectors should be larger than 3d₀ to avoid the shear fracture of the plate end. When bearing failure at bolt hole occurred, the bearing capacity gradually increased with the increase of bolt preloading. The calculation formula of the bearing capacity of CSP connectors was suggested to be multiplied by the increase factor of 1.1 on the basis of the calculation formula of China for calculating flat plate connectors. When bolt shearing failure occurred, bolt preloading had little effect on bearing capacity, and the calculation formula of the bearing capacity of CSP connectors could be calculated as that of flat plate connectors.