Performance-based design for a constructional steel frame in nonlinear-plastic region requires an improvement in order to achieve a reliable structural analysis.The need to explicitly consider the nonlinear behaviour ...Performance-based design for a constructional steel frame in nonlinear-plastic region requires an improvement in order to achieve a reliable structural analysis.The need to explicitly consider the nonlinear behaviour of structures makes the numerical modelling approach much more favourable than expensive and potentially dangerous experimental work.The parameters considered in the analysis are not limited to the linear change of geometry and material yielding,but also include the effect of large deformations,geometrical imperfections,load eccentricities,residual stresses,strain-unloading,and the nonlinear boundary conditions.Such analysis requires the use of accurate mathematical modelling and effective numerical procedures for solving equations of equilibrium.With that in mind,this paper presents the mathematical formulations and finite element procedures of nonlinear inelastic steel frame analysis with quasi-static semi-rigid connections.Verification and validation of the developed analytical procedures are conducted and good agreements are obtained.It is an approach that enables the structural behaviour of constructional steel frames to be traced throughout the entire range of loading until failure.It also provides information on the derivation of the structural analysis by using finite element method.展开更多
Tenon-mortise joint is widely used in traditional timber structures around the world.This paper summarizes the results of an experimental study of the structural behavior of tenon-mortise joints made with glulam and C...Tenon-mortise joint is widely used in traditional timber structures around the world.This paper summarizes the results of an experimental study of the structural behavior of tenon-mortise joints made with glulam and CNC technology instead of traditional material and manual work.30 full-scale tenonmortise joints were manufactured and tested under monotonic loading,and the effects of dimension,shape,processing error and adhesive were evaluated.It was found that the round rectangular shaped tenon-mortise joints were comparable with traditional joints in terms of structural performance,but were time and labor saving.The variability of the proposed tenon-mortise joints was lower,which would benefit the design value.Applying adhesive between tenon and mortise increased the average stiffness by 4.3 times and average moment capacity by 27.4%,respectively.The gaps between wood members had little effect on the capacity and stiffness in monotonic bending but may influence the energy dissipation ability in cyclic bending.This study showed the feasibility of combining the traditional joinery method with modern wood products and manufacturing technology,which may promote the application of tenon-mortise joints in modern timber structures.展开更多
Based on molecular mechanics and the deformation characteristics of the atomic lattice structure of graphene, a modifi ed molecular structure mechanics method was developed to improve the original one, that is, the se...Based on molecular mechanics and the deformation characteristics of the atomic lattice structure of graphene, a modifi ed molecular structure mechanics method was developed to improve the original one, that is, the semi-rigid connections were used to model the bond angle variations between the C-Cbonds in graphene. The simulated results show that the equivalent space frame model with semi-rigid connections for graphene proposed in this article is a simple, efficient, and accurate model to evaluate the equivalent elastic properties of graphene. Though the present computational model of the semi-rigid connected space frame is only applied to characterize the mechanical behaviors of the space lattices of graphene, it has more potential applications in the static and dynamic analyses of graphene and other nanomaterials.展开更多
This paper presents a simplified beam design method for semi-rigid composite frames with vertical loading at the serviceability limit state. Equations were developed to determine the deflections of the composite beam ...This paper presents a simplified beam design method for semi-rigid composite frames with vertical loading at the serviceability limit state. Equations were developed to determine the deflections of the composite beam allowing for both joint flexibility and beam sectional properties, along with a formula for the connection secant stiffness. The equations for the connection stiffness are more accurate than previous equations used because it considers the beam-to-column stiffness ratio and the beam-to-connection stiffness ratio. The equations were validated by the experimental results for two semi-rigid composite frames. The equations agree well with the experimental data because they take into account the actual beam-to-column connections and the composite action between the steel beam and the concrete slab.展开更多
基金The authors would like to acknowledge the supports from Universiti Teknologi Malaysia(UTM)and Ministry of Higher Education(MOHE).
文摘Performance-based design for a constructional steel frame in nonlinear-plastic region requires an improvement in order to achieve a reliable structural analysis.The need to explicitly consider the nonlinear behaviour of structures makes the numerical modelling approach much more favourable than expensive and potentially dangerous experimental work.The parameters considered in the analysis are not limited to the linear change of geometry and material yielding,but also include the effect of large deformations,geometrical imperfections,load eccentricities,residual stresses,strain-unloading,and the nonlinear boundary conditions.Such analysis requires the use of accurate mathematical modelling and effective numerical procedures for solving equations of equilibrium.With that in mind,this paper presents the mathematical formulations and finite element procedures of nonlinear inelastic steel frame analysis with quasi-static semi-rigid connections.Verification and validation of the developed analytical procedures are conducted and good agreements are obtained.It is an approach that enables the structural behaviour of constructional steel frames to be traced throughout the entire range of loading until failure.It also provides information on the derivation of the structural analysis by using finite element method.
文摘Tenon-mortise joint is widely used in traditional timber structures around the world.This paper summarizes the results of an experimental study of the structural behavior of tenon-mortise joints made with glulam and CNC technology instead of traditional material and manual work.30 full-scale tenonmortise joints were manufactured and tested under monotonic loading,and the effects of dimension,shape,processing error and adhesive were evaluated.It was found that the round rectangular shaped tenon-mortise joints were comparable with traditional joints in terms of structural performance,but were time and labor saving.The variability of the proposed tenon-mortise joints was lower,which would benefit the design value.Applying adhesive between tenon and mortise increased the average stiffness by 4.3 times and average moment capacity by 27.4%,respectively.The gaps between wood members had little effect on the capacity and stiffness in monotonic bending but may influence the energy dissipation ability in cyclic bending.This study showed the feasibility of combining the traditional joinery method with modern wood products and manufacturing technology,which may promote the application of tenon-mortise joints in modern timber structures.
基金Funded by the Talent Foundation and Youth Foundation of Xi’an University of Architecture and Technology(Nos.DB12062 and QN1239)
文摘Based on molecular mechanics and the deformation characteristics of the atomic lattice structure of graphene, a modifi ed molecular structure mechanics method was developed to improve the original one, that is, the semi-rigid connections were used to model the bond angle variations between the C-Cbonds in graphene. The simulated results show that the equivalent space frame model with semi-rigid connections for graphene proposed in this article is a simple, efficient, and accurate model to evaluate the equivalent elastic properties of graphene. Though the present computational model of the semi-rigid connected space frame is only applied to characterize the mechanical behaviors of the space lattices of graphene, it has more potential applications in the static and dynamic analyses of graphene and other nanomaterials.
基金the National Science Fund for Distinguished Young Scholars (No. 50225825)
文摘This paper presents a simplified beam design method for semi-rigid composite frames with vertical loading at the serviceability limit state. Equations were developed to determine the deflections of the composite beam allowing for both joint flexibility and beam sectional properties, along with a formula for the connection secant stiffness. The equations for the connection stiffness are more accurate than previous equations used because it considers the beam-to-column stiffness ratio and the beam-to-connection stiffness ratio. The equations were validated by the experimental results for two semi-rigid composite frames. The equations agree well with the experimental data because they take into account the actual beam-to-column connections and the composite action between the steel beam and the concrete slab.