Chord Width Research Articles

Design, hydrodynamics analysis, and control of an underwater glider with controllable wing mechanism

Due to the effect of biofouling and different mission sensors that may be onboard, hydrodynamic coefficients of underwater glider (UG) may experience gradual or obvious changes, which increases the energy consumption and reduces the glide range. This paper proposes a controllable wing mechanism (CWM) for UG, which enables it adjust the hydrodynamic coefficients and kinematic performance without changing the net buoyancy. Only by two degrees of freedom (DoF), that CWM can realize the control of wingspan, sweep back angle and chord width. To apply the hydrodynamics controlled with CWM in glide model, the fitting precision of hydrodynamics function is improved based on backpropagation artificial neural network (BPANN). A nonlinear state observer based on finite impulse response (FIR) filter is employed for state estimation and random noise interference filtering to realize measurements and evaluation of velocity and reduce the attitude angle measurement error for UG. Then, the FIR-based fuzzy PID (FFPID) controller is established for a steady-state gliding motion control, which suppresses the unknown interference to stablize the system quickly. Finally, the effectiveness of the FFPID closed-loop controller and observer is verified through the simulation in matlab and the experimental test of the UG with CWMs in a water tank.

Forensic evaluation of craniometric characteristics of the Kazakhstan population

BackgroundThe human skull is the part of the skeleton most frequently used in population studies, as it was more exposed to genetic factors and less exposed to environmental factors. The skull is an important component in human forensic identification. Materials and methodsThe craniometric characteristics of 186 male and 114 female skulls found on the territory of Kazakhstan were studied. Dimensions were measured using standard anthropometric methods and instruments. The results of measurements of 25 craniometric parameters are presented. Methods of descriptive and parametric statistics were used. ResultsStatistical analysis showed significant regional dimorphism, confirming theindividuality of the Kazakhstan population. Statistically significant deviations werefound in 6 male craniometric characteristics and 4 female craniometric characteristics(p<0.05). The most dimorphous variables for regional identification in Kazakhstanmales were the higher skull base and frontal chord width , full face height , condylarand bigonial width , and low mandibular body reference values (p<0.05). For females,significant statistical discrepancies were seen in the transverse diameter and skullbase width, mastoid and occipital aperture width (p<0.05). ConclusionThe recorded variations and changes in the morphology of the humanskull of the population of Kazakhstan indicate the need to develop and updateosteometric standards used in practice for specific populations. All this will significantlyimprove the accuracy of forensic identification and more fully study the biologicalpatterns of population formation, as well as evaluate the comparative effectiveness ofindividual features in the reconstruction of the population history of various populationgroups.

Maximisation the autonomous flight performance of unmanned helicopter using BSO algorithm

AbstractThe usage areas of rotary or fixed wing unmanned aerial vehicles (UAV) have become very widespread with technological developments. For this reason, UAV designs differ in terms of aerodynamic design, flight performance and endurance depending on the intended use. In this study, maximising of the autonomous flight performance of the unmanned helicopter produced at Erciyes University using an optimisation algorithm is discussed. For this purpose, the input parameters of the dynamic model are chosen as blade length, blade mass density, blade chord width and blade twist angle of the unmanned helicopter and the proportional, integral, derivative gain coefficients of the lateral axis of the autopilot. The output parameters of the dynamic model are selected as settling time, rise time and maximum overshoot, which are autonomous performance parameters. The dynamic model consisting of helicopter and autopilot parameters is integrated into the back-tracking search optimisation (BSO) algorithm as an objective function. In the optimization process, where mean squared error (MSE) is used as the performance criterion, optimum input and output values were determined. Thus, helicopter and autopilot parameters, which are among the factors affecting autonomous performance, are taken into account with equal importance and simultaneously. Simulations show that the obtained values are satisfactory. With this approach based on the optimisation method, complex and time-consuming dynamic model calculations are reduced, time and cost are saved, and practicality is achieved in applications. Therefore, this approach can be an innovative and alternative method to improve UAV designs and increase flight performance compared to classical methods.

Experiments and investigation of planar high-strength steel joints with Additive Manufacturing

This paper investigates the application of high-strength steel in planar steel joints, specifically X-joints and T-joints, which are crucial connecting components in structural engineering, ensuring structural stability in buildings, bridges, and tower cranes. Conventional steel joints, mainly constructed from low-carbon steel, encounter challenges arising from the low ductility of high-strength steel and its strict welding criteria. The Solid Isotropic Material with Penalization (SIMP) method is employed to perform topology optimization on X-joints with different brace width to chord width ratios and T-joints, enabling the manufacturing of high-strength steel components through the Additive Manufacturing method (AM). The impact of different additive manufacturing orientations on material strength is tested, with results indicating improved mechanical properties when the loading direction is perpendicular to the normal direction of the additive manufacturing layer. Compression tests are conducted using 2D/3D Digital Image Correlation methods (2D/3D-DIC) alongside traditional measurement techniques. The results indicate that the stress distribution of the optimized joint is more rational, and the strength of the optimized joint has improved compared to the tubular joint. The optimized joint exhibits a more distinct load path and apparent failure mode. This optimized joint enables a uniform stress redistribution, enhancing ductility and achieving a strong-joint and weak-component structural mechanism that satisfies the serviceability limit state (SLS). In comparison to non-penetrative tubular joints, no significant cracks are observed under identical loading conditions.

Tensile behaviour of welded S700 rectangular hollow section X‐joints

AbstractHigh‐strength steels (HSS) have higher strength but lower ductility compared to mild steels. A material factor (Cf) and a 0.8fu restriction on the material design yield strength (fy) are stipulated to reduce the design resistance of welded HSS hollow section joints in the newest version of prEN 1993‐1‐8 (2022), given the low ductility of HSS and a limited number of experiments on welded HSS joints. However, applying the material factor and the yield strength restriction partially eliminates the benefits of using HSS, limiting its competitiveness. Besides, the type of the weld (fillet weld or butt weld), which is not distinguished in the design rules in prEN 1993‐1‐8 (2022), may influence the mechanical behaviour of the joint. Hence, in this paper, a parametric study is carried out based on the validated Gurson‐Tvergaard‐Needleman (GTN) damage model and the validated finite element (FE) model of two X‐joints in literature. The effect of two parameters, the brace width to chord width ratio (β) and the weld dimension, on the tensile behaviour of the welded S700 rectangular hollow section (RHS) X‐joint are evaluated. The FE results are compared to the prEN 1993‐1‐8 prediction, and the necessity of Cf and the 0.8fu yield strength restriction is evaluated.

New proposal for the bending moment capacity of tubular T-joints in carbon steel and stainless steel structures

The expected failure mode of T-joints between rectangular hollow sections subjected to bending moment with a ratio of the brace width (b1) over the chord width (b0) below 0.85 (i.e., β=b1/b0≤0.85) is the chord face failure, produced by yielding. This paper presents the development of a numerical model to reproduce this phenomenon, calibrated against experimental laboratory tests, which is then used to carry out a large parametric study, where the influence of the main geometric parameters involved in the joint resistance –the chord width (b0), the chord thickness (t0), the chord radius (R0), the brace width (b1), the brace height (h1) and the weld thickness (a)– is assessed for two different materials: S275 carbon steel and EN 1.4301 austenitic stainless steel. The results derived from the parametric study suggested that a different yield line mechanism may develop for higher β-values (β≥0.45) than that considered in current European and American codes. Hence, a new formulation for estimating the bending resistance of T-joints exhibiting chord face failure modes is presented based on a different yield line mechanism developed in this paper. This formulation includes additional geometric parameters that are dismissed in the current formulation, such as the chord radius and the weld thickness, which are found to have a non-negligible influence on the joint resistance. Moreover, the proposed formulation is adjusted in order to be used for joints with lower β-values without losing accuracy. Additionally, the new proposed formulation is adapted for stainless steel joints by combining it with the Continuous Strength Method (CSM) formulation with promising results. Finally, the soundness and safety of the proposed formulation is statistically demonstrated.

Numerical analysis of novel concrete filled K joints with different brace sections

All over the world, truss structures are commonly used in long-span bridge. Since joint is the weakest part of this structure, this paper proposes a novel type in which different brace members are used in the concrete filled box section K-joints. This novel type is designed as rectangular compression brace with the brace width to chord ratio β<0.8 and chord welded tension brace (β=1). That configuration allows to reduce the gap, thus eliminate the secondary moment. Moreover, load transfer and failure modes are not similar to the ordinary. Numerical simulation is the used method of investigation in which validation is carried out through thirty-four models composed of RHS K gap Joint – CFST T Joint – CFST Y Joint – RHS T Integral Joint – CFST K gap Joint. Difference between experiments and Finite Element models are less than 20% thus acceptable. Through the validated numerical simulation model, analysis of suitable boundary conditions and variation of initial stiffness, ultimate strength are presented in accordance with the novel joint parameters. Comparison of the novel joint type to the rectangular hollow section (RHS) and rectangular concrete filled steel tube (RCFST) is carried out in terms of initial stiffness and ultimate strength. Finally, optimization of the novel type of joint is proposed for engineering practice so as to have overview of the strength in practical aspect. Results have shown that most of the proposed types of boundary condition procure the joint deformation while subjected in compression and tension load. Tension brace failure is the typical failure mode of the novel joint in which the chord width, the parameter β are fundamental and directly proportional to the joint initial stiffness and ultimate strength. For β=0.8 and the chord width between 500 and 1000 mm, the initial stiffness can vary from [9944.92kN/mm−19887.31kN/mm]; ultimate strength varies from [29551.76kN−117916.20kN]. Moreover, the novel joint type is stronger than the RHS and the RCFST in both initial stiffness and ultimate strength. That difference is about 3–6% in the initial stiffness and around 10% for the ultimate strength. These demonstrate that the novel type of joint is acceptable in engineering truss bridge with proposition of joint optimization.

Study of the conditional flexibility effect of compressed chord on the overall stability of corrugated beams

In this paper, the calculation of cut corrugated beams loaded with uniformly distributed load in the plane of the wall, with a wall height of 333 and 500 mm (54 sizes), chord width from 160 to 400 mm and chord thickness from 6 to 30 mm for general stability in accordance with Building Codes (BC) 294.1325800.2017 is made. A geometric criterion has been defined which defines the boundaries of the load-carrying capacity of Russian corrugated beams between the flat bending form stability and the strength of the normal section under the action of the bending moment in the plane of the wall.

Ultimate capacity of SHS X-joints made of normal and high-strength weathering steels

The aim of the current work is to study the static strength properties of welded tubular X-joints made of weathering steel. Quasistatic tensile and compression tests were carried out on welded tubular X-joints made of three weathering steel grades. The X-joints were manufactured from squared hollow section (SHS) tubes of 355WH, 500WH and 550WH weathering steel materials and prepared using gas metal arc welding with a LNM 28 solid wire (diam. 1 mm) as a welding consumable. Both joints with equal and unequal brace width to chord width (β = b1/b0) ratios were studied and a total number of 17 quasistatic tests on the X-joints were conducted, of which four specimens were tested in compression and 13 were tested in tension. In addition, flat coupon specimens were manufactured from the weld sections of the joints with the ratio of β = 1.0 for quasistatic testing, supported by the macrographical investigations, hardness measurement and scanning electron microscopy (SEM) analysis at the joint area. The obtained experimental ultimate capacities exceeded the design resistances for axially loaded joints as per the Eurocode 3 standard and the results thus indicated that the present standard can be used for design purposes of tubular joints made of weathering steels. The investigated high-strength weathering steel grades suffered from the strength reduction due to the welding and the limitations regarding heat inputs should be carefully considered.

Numerical Investigation of Doubler Plate Reinforced Tubular T‐joints under Chord Compression Loads

AbstractTubular profiles present geometric properties that enable a better structural behaviour in comparison with other cross‐sections when subjected to torsion. In regards to the joints between its elements, there are a few parameters that govern the design of the T‐joint resistance and change its failure mode. This paper presents a numerical investigation of square hollow sections (SHS) T‐joints with doubler plate reinforcement on the upper chord face under axial compression. The geometrical parameters are the slenderness chord, brace to chord width ratio, and reinforcement plate thickness combined with a certain level of axial compression on the chord. A numerical model has been developed compared with experimental tests. In addition, a parametric study was performed based in order to evaluate the parameters that influence the structural behaviour of reinforced T‐joint. Concerning outcomes, the increase of reinforcement plate thickness was responsible for the improvement of the joint capacity. In opposite to recommended by actual codes, the compression applied on the chord reduced the joint resistance mainly for those slender chord wall. Comparing with formulation from both code and other works, it was possible to conclude that there is an unsafe level from the actual codes.

Fire resistance of reinforced SHS T-joints considering gradient temperature effect under post-earthquake fire

The earthquake usually causes serious damage on the T-joints in structure, which may reduce its fire resistance. Moreover the gradient temperature distribution for reinforced SHS T-joints appears under a fire. Therefore it is very necessary to evaluate the fire resistance of reinforced SHS T-joint considering gradient temperature effect under post-earthquake fire (PEF). The objective of this paper is to investigate the fire resistance of earthquake-damaged doubler-plate reinforced SHS T-joints considering gradient temperature effect. A computation model was established and validated using the existing experimental results. The gradient-temperature field distribution against reinforced SHS T- joints was conducted by transient-response analysis method, then a parametric study was carried out using 30 established computation models involving following dimensionless parameters such as the width ratio of brace to chord (δ), diameter to thickness ratio of chord (ζ), wall thickness ratio of doubler-plate to chord (α), wall thickness ratio of brace to chord (ε), length ratio of doubler-plate to chord (ξ), ratio of chord length to chord width (φ), welding effect, damage variable (D~) and fire retardant coating thickness. The results demonstrated that damage variable and fire retardant coating thickness had a great influence on the fire resistance of doubler-plate reinforced SHS T-joints, the parameters δ, ζ and α had a major influence on reinforced SHS T-joints. The findings can provide data support and theoretical reference for the design, maintenance and reinforcement of such joints.

Three-Dimensional Numerical Simulation of a Flat Plate Perpendicularly Submitted to Current With a Blockage Ratio of 0.214: URANS and Detached Eddy Simulation

Abstract The uniform flow over a nominally two-dimensional normal thin flat plate with blockage ratio 0.214 was numerically investigated in three dimensions by three methods: unsteady Reynolds-averaged Navier–Stokes (URANS) based on the realizable k–epsilon (RKE) turbulence model, URANS based on the k–omega shear stress transport (SST) turbulence model, and detached eddy simulation (DES). The Reynolds number based on the inlet flow velocity and the chord width of the plate was 117,000. A comprehensive comparison against earlier experimental results showed that URANS-SST method only could give a correct Strouhal number but overestimated the mean base pressure distribution and mean drag coefficient, while URANS-RKE and DES methods succeeded in giving accurate predictions of all. Moreover, by comparing the instantaneous vorticity contours and three-dimensional (3D) turbulent flow structures, it is found that DES is better suited for the present case because it can capture irregular small-scale structures and reproduce the three-dimensionality and low-frequency unsteadiness of the vortex shedding. Finally, through the volume-of-fluid (VOF)-based simulation of the free surface, it is demonstrated that the free surface has no significant effect on the mean drag coefficient and Strouhal number.

Integrated design framework of 3D printed planar stainless tubular joint: Modelling, optimization, manufacturing, and experiment

Nowadays, tubular joints with superior structural properties have been extensively applied in constructing the complicated multi-planar steel joints that are often adopted in the grid shell structure system. However, sometimes it is challenging to maintain high-quality on-site welding joints or even difficult to assess the quality of on-site welding, especially for the overhead welding. This paper presents an integrated design framework of the 3D printed planar stainless tubular joint, and this framework is implemented by Solid Isotropic Material with Penalization Method (SIMP). Three joints with different brace to chord width ratios are optimized, and the re-engineered joints are obtained using computer-aided design software. Joints independently designed and manufactured by 3D printing methods can be riveted with other structural members to simplify the installation process and improve the construction efficiency, thus reducing the difficulty of on-site welding. Non-contact 2D DIC (Digital Image Correlation) is used to analyze the strain distribution more intuitively for 3D printed and welding planar tubular joints. Moreover, the coupon tensile test is proposed to analyze the stress–strain relationship when considering different printing orientations. Experiments show that the orientation of material additive manufacturing affects the yield strength, ultimate strength and elongation at fracture to a certain extent but has little influence on Young’s modulus. The optimized joint exhibits different failure modes than the traditional tubular joints, which can achieve strong-joint and weak-component mechanisms and avoid failure of the entire joint when local damage occurred. In addition, the plump curve according to the hysteresis loop suggests that the energy dissipation of the optimized joint is larger than the traditional welding joint, which is beneficial to enhance the seismic performance of the structures. The developed framework can also be extended to the complex spatial joints, which is subjected to multi-planar loads in the future.

Behavior of partially concrete-filled X-joints with CHS braces and SHS chord under axial compression

The paper experimentally studies the static behavior of partially concrete-filled X-joints with circular hollow section (CHS) braces and square hollow section (SHS) chord under axial compression. Totally 40 partially concrete-filled CHS-SHS X-joints were designed, including 20 X-joints with concrete-filled CHS braces and hollow SHS chord (CFCHS-SHS) and 20 X-joints with hollow CHS braces and concrete-filled SHS chord (CHS-CFSHS). The impacts of the brace diameter to chord width ratio (β = d/b) and chord width to double chord thickness ratio (γ = b/2 T) on the static behavior of CHS-SHS X-joints were experimentally studied. At the same time, the corresponding finite element analysis (FEA) models were established and validated by comparison with test results, and then an extensive parametric investigation was performed to study the effects of three main influential factors (τ, concrete filling position, and in-filled concrete strength) on the ultimate strength of CHS-SHS X-joints under axial compression. The test results show that the CFCHS-SHS X-joints and CHS-CFSHS X-joints exhibit completely different failure modes under axial compression. All CFCHS-SHS X-joints are failed with chord plasticization, while the local buckling of the brace members is the primary failure mode for the CHS-CFSHS X-joints. The ultimate strength and axial stiffness of CHS-CFSHS X-joints are significantly higher than those of CFCHS-SHS X-joints. However, the ductility of CHS-CFSHS X-joints is slightly superior to that of CFCHS-SHS X-joints. Based on the analyses of test results, the design equations derived from the simplified yield line model were put forward for the estimation of the ultimate strength of CFCHS-SHS X-joints, which was verified to be reasonable and accurate. In addition, the study also revealed that the total cross-section yield strength of the brace could be utilized to accurately predict the ultimate strength of CHS-CFSHS X-joints.

Experimental and numerical studies on stress concentration factors of high strength steel fabricated box X-joints

High strength steel (HSS) is commonly available in the form of steel plates. The built-up box tube with sharp corners which is welded from four steel plates is usually fabricated for construction. The stress concentration factor (SCF) is crucial for the determination of the hot spot stress range which governs the high-cycle fatigue resistance of tubular joints. This paper presents experimental and finite element (FE) investigations on the SCF of HSS fabricated box X-joints. Four X-joints which are fabricated from built-up box tubes with a nominal yield stress of 890 MPa are tested under brace axial compression. The SCFs at typical hot spot locations are obtained using strip strain gauges. A FE model which has been validated against the test results is employed to conduct the parametric study on totally 112 fabricated box X-joints. The loading cases of brace and chord axial loading are covered. The effects of brace to chord width ratio, chord width to wall thickness ratio and brace to chord wall thickness ratio on the SCFs at the hot spot locations are revealed. The CIDECT SCF formulae are shown to be not suitable for the fabricated box X-joints under brace and chord axial loading. More accurate SCF equations are proposed to calculate the SCFs at the hot spot locations of the box X-joints.

Numerical investigation and design rules for stress concentration factors of stainless-steel hybrid tubular joints

This paper describes a numerical study on stress concentration factors (SCFs) of stainless-steel hybrid tubular T-, Y- and X-joints with circular hollow sections (CHSs) and with square hollow sections (SHSs). The finite element models (FE models) were developed and validated against the corresponding test results available in the literature. The validated FE models were then utilized to perform an extensive parametric study containing 47 FE models for T-joints, 47 FE models for Y-joints and 47 FE models for X-joints. In total, 141 FE models were analyzed in the parametric study. The brace diameter to chord width ratio (β=d1∕b0), brace to chord thickness ratio (τ=t1∕t0) and chord width to thickness ratio (2γ=b0∕t0) were selected as the key geometric parameters in the parametric study. The SCFs at the hot spot locations obtained from the parametric study were compared against those calculated from the design formulae specified in the current design guidelines of the International Committee for the Development and Study of Tubular Structures (CIDECT). The comparison results show that the design formulae given in the CIDECT specification are not appropriate for predicting the SCFs of stainless-steel CHS-to-SHS hybrid tubular T-, Y- and X-joints. Therefore, new design equations were proposed in this study. It is shown that the values of SCFs calculated from the proposed design equations are generally in good agreement with the values obtained from the FEA.

Mechanical behaviour of welded high strength steel rectangular hollow section joints

The material reduction factor of rectangular hollow section (RHS) joints in a new version of Eurocode 3 part 1–8 is validate for steel with the nominal yield strength up to 700 MPa. In this paper, finite element simulations of gap K-joints are conducted to investigate effects of material properties, gap size of the joint, the brace to chord width ratio and welds type on the secondary bending stresses and the resistance. The governing failure mode considered for all the FE models is the chord face failure followed by brace sidewall failure. The ratio of axial stresses to the nominal stress was lower in the compressive brace made of higher strength steel grades compared to the mild strength grades. The maximum secondary bending stresses is 0.12–0.32 yield strength. The secondary bending stresses are increasing with the increase of the steel grade and the brace to chord width ratio and with reducing the gap size. The level of secondary bending stresses varied between 38% and 56% of the average normal axial stress. The secondary bending stresses of fillet-welded joints are larger than the butt-welded joints. The yield line model is used to predict the ultimate load and good agreement is obtained compared with FE results.

Experimental and numerical research on fire resistance of stainless steel tubular X-joints

The fire test was carried out on six stainless steel square hollow section (SHS) tubular X-joints to investigate the influences of axial loading ratio in brace member, brace to chord width ratio and inclined angle between brace and chord member on the fire resistance performance of joints. The furnace temperature-time curve, surface temperature-time curve, vertical deformation-time curve, lateral deformation of chord web-time curve and failure mode for all specimens were obtained by the fire test. The test results show that, the failure modes of stainless steel SHS tubular X-joints at elevated temperatures can be divided to three types: plastic failure of chord flange, plastic failure of chord flange and web, and buckling failure of chord web. Then, the failure criterion of stainless steel SHS tubular X-joints under fire conditions was proposed: the joint can be considered to be damaged when its concave deformation of chord flange reaches 0.03 times of chord width. The finite element models of stainless steel SHS tubular X-joints were established and validated against the test data. Finally, based on the validated models, a parametric analysis was performed on the influencing factors of the fire resistance of tubular joints, and the results show that the failure temperature of stainless steel SHS tubular X-joints will be enhanced with the increase of brace to chord width ratio and chord width to thickness ratio, or with the decrease of axial loading ratio in brace member and chord preload ratio.

Improvement of wind turbine aerodynamic performance by vanquishing stall with active multi air jet blowing

The effects of jet blowing on blade suction side of NREL phase VI horizontal axis wind turbine (HAWT) for alleviation of degraded flow due to boundary layer separation were investigated. A 3D innovative multi-jet blade is simulated using FLUENT 18.2 software applying SST k-ω turbulence model. The spanwise blade portions for jets are outer, middle and inner. Furthermore, twelve jets with 0.04 local chord width have deployed in four chordwise locations of x/c = 0.1, x/c = 0.3, x/c = 0.5 and x/c = 0.7. The torque is sensitive to some dimensionless parameters such as Tip Speed Ratio (TSR) and jet velocity ratio (VR). At the best condition, torque increases about two times with respect to baseline blade. The jet velocity ratios are 1.2, 2.0, 2.4, 2.8, and 3.2.Applying changes in jet parameters, the flow pattern and quality improved. Also, the aerodynamic torque synergy of combinations of two, three and four jets were compared with that of a single jet and the direct relationship between the number of activated jets and the increase in torque was proved. The results showed that jets in blade outer part, have more effects in aerodynamic performance of rotor than the other blade portions. T1 jet produced the highest increase in torque.

Finite element analysis on the residual bearing capacity of axially preloaded tubular T-joints subjected to impacts

Understanding the dynamic behavior of tubular members is necessary for ensuring their safety, even when damaged after an impact. A nonlinear finite element analysis (FEA) was performed to evaluate the residual bearing capacity of axially preloaded square hollow section (SHS) T-joints subjected to impact loading. First, the Bao–Wierzbicki fracture criterion was used to simulate the failure modes and behavior of specimens subjected to static axial compression and impacts, and the numerical results were compared with experimental results in the literature. The bearing capacity error between the numerical and experimental results was within 10%, which verified the accuracy of the finite element (FE) model. Then, the local and global displacements of joints were distinguished with the central line displacement method, and 40 FE models were created. The dynamic responses of joints under impact loading were used to study the resistance mechanism. Joint deformation mainly manifested as outward buckling of the chord webs and indentation of the chord upper flange. The in-plane restraint and support by the brace of the chord increased with the brace–chord width ratio. Finally, the ultimate residual bearing capacity coefficient ψ was defined as the ratio of the ultimate bearing capacities of the impacted and reference specimen, and the influence of different parameters, including axial preloading, impact energy, brace–chord width ratio, and chord diameter, was explored. Axial preloading and impact energy showed a negative correlation with ψ, while the brace–chord width ratio and chord diameter showed a significant positive correlation with ψ.