The Experts below are selected from a list of 51735 Experts worldwide ranked by ideXlab platform

Yong Wang - One of the best experts on this subject based on the ideXlab platform.

  • analytical model for predicting the load deflection Curve of post fire reinforced concrete slab
    Fire Safety Journal, 2018
    Co-Authors: Yong Wang, Wenxuan Guo, Zhaohui Huang, Bangyun Long, Guanglin Yuan, Weinan Shi, Yajun Zhang
    Abstract:

    Abstract This paper firstly presents the experimental results of two simply supported full-scale reinforced-concrete (RC) slabs (unheated and fire-damaged). Thereafter, an analytical model for predicting the load–deflection Curves of post-fire RC slabs is described in detail. The model can predict ultimate loads and displacements in both post-fire RC slabs and those at ambient temperature. The developed model has been validated using test data generated in this research and previous research and compared with a few analytical models developed by other researchers; some of the proposed model's advantages are highlighted in this paper. Results indicate that the model can be employed to determine the residual strength of post-fire RC slabs with reasonable accuracy. It is evident that steel strain differences and vertical shear forces in the slab have considerable effects on the load-carrying capacities of unheated and fire-damaged RC slabs.

  • shear and bending behaviour of fin plate connection to concrete filled rectangular steel tubular column development of a simplified calculation method
    Journal of Constructional Steel Research, 2010
    Co-Authors: M H Jones, Yong Wang
    Abstract:

    Abstract This paper presents the results of numerical and theoretical studies into the behaviour of simple welded fin-plate to concrete-filled tubular (CFT) columns loaded by tensile force. Such connections represent a simple single-sided joint solution to steel CFTs. The current design method for similar connections under purely tensile load, in CIDECT Guide 9, based on a deformation limit of 0.03 of the tube width is shown to be inadequate when evaluating the ultimate strength of such connections. Hence numerical models have been developed and used to perform extensive parametric studies from which a simple hand calculation method has been developed for evaluating the strength of the column component of rectangular CFTs under tensile load imparted through a fin-plate connection. The ranges of parameters encompassed by the model include column cross-section size, column thickness and fin-plate length. The simple hand calculation procedure is based upon defining a rigid plate deformation pattern for the column face and then applying the virtual work principle. The column face deformation corresponding to the maximum load has been found to be strongly related to the column width to thickness ratio and a method for evaluating this relationship has been proposed based on extensive numerical results. The load–deflection Curve consists of two segments: the first representing the elastic behaviour from classic plate theory, the second obtained by plotting the deflection at failure against failure load — both of which are obtained through the simple hand calculation procedure. The simple hand calculation method is compared favorably with a large range of finite element simulations. The proposed method may be used in the component based method for joints involving a fin-plate component in tension.

  • shear and bending behaviour of fin plate connection to concrete filled rectangular steel tubular column development of a simplified calculation method
    Journal of Constructional Steel Research, 2010
    Co-Authors: M H Jones, Yong Wang
    Abstract:

    Abstract This paper presents the results of numerical and theoretical studies into the behaviour of simple welded fin plate to concrete filled tubular (CFT) columns loaded by bending and shear force. Such connections represent a simple single-sided joint solution to steel CFTs and are commonly used in practice. The current design guidance encapsulated in CIDECT Guide 9 does not cover the ultimate strength of such connections. Hence numerical models have been developed and used to perform extensive parametric studies from which a simple manual calculation method has been developed for evaluating the strength of the column component of rectangular CFTs under shear and bending load imparted through a fin plate connection. The ranges of parameters encompassed by the model include column cross-section size, column thickness and fin plate length. The simple manual calculation procedure is based on defining a rigid plate deformation pattern for the column face and then applying the virtual work principle. The column face deformation corresponding to the maximum load has been found to be strongly related to the column width to thickness ratio and a method for evaluating this relationship has been proposed based on extensive numerical results. The load–deflection Curve consists of two segments: the first representing the elastic behaviour from classic plate theory, the second obtained by plotting the deflection at the maximum load against the maximum load, both of which are obtained through the simple manual calculation procedure. The simple manual calculation method is compared favorably with a large range of finite element simulations. The proposed method may be used in the component based method for joints involving a fin plate component in shear and bending.

Zemei Wu - One of the best experts on this subject based on the ideXlab platform.

  • effects of steel fiber content and shape on mechanical properties of ultra high performance concrete
    Construction and Building Materials, 2016
    Co-Authors: Zemei Wu, Wen He, Linmei Wu
    Abstract:

    Abstract This study investigated the effects of three shaped steel fibers (straight, corrugated, and hooked-end) with different fiber contents by volume (Vf = 0, 1%, 2%, and 3%) on mechanical properties of ultra high performance concrete (UHPC). The involved properties included flowability, compressive strength, and flexural behavior. According to the characteristics of the obtained three-point flexural load–deflection Curve and the existing constitutive model of uniaxial compression, a new model for flexural load–deflection based on least square fitting was proposed. The results indicated that increased fiber content and use of deformed fibers could gradually decrease the flowability of UHPC. They also had significant effects on compressive and flexural behavior of UHPC. With incorporation of 3% straight steel fibers, its compressive and flexural strengths reached over 150 and 35 MPa at 28 d. For the concrete with 3% hooked-end and corrugated fibers, the compressive strengths at 28 d increased by 48% and 59% compared to those with the same amount of straight fiber. Steel fiber content had limited effect on the first crack strength and first crack deflection of flexural load–deflection Curve of UHPC, but showed considerable effects on the peak load. The proposed model fitted well with the experimental results with correlation coefficient over 0.9.

R Ansari - One of the best experts on this subject based on the ideXlab platform.

  • nonlinear bending of third order shear deformable carbon nanotube fiber polymer multiscale laminated composite rectangular plates with different edge supports
    European Physical Journal Plus, 2018
    Co-Authors: R Gholami, R Ansari
    Abstract:

    The geometrically nonlinear bending behavior of carbon nanotube/fiber/polymer multiscale laminated composite (CNT-FPMLC) rectangular plates with various edge conditions subjected to the uniform transverse mechanical loading is investigated. Based on the Reddy’s third-order shear deformation plate theory and employing the von Karman hypotheses and fundamental lemma of calculus of variations, the governing equilibrium equations including the shear deformation effect and geometrical nonlinearity together with associated boundary conditions are developed. The fiber micromechanics and the Halpin-Tsai relations are employed to approximately calculate the material properties of multiscale composite. Also, the carbon nanotubes (CNTs) are assumed to be distributed uniformly and oriented arbitrarily through the epoxy resin matrix. For the large deflection analysis, first, the generalized differential quadrature (GDQ) method is used to discretize the differential governing equations and corresponding boundary conditions resulting in a set of nonlinear algebraic equations. Then, the pseudo-arclength continuation technique is utilized to numerically solve the resulting nonlinear parameterized equations and subsequently obtain the Load-Deflection Curve of CNT-FPMLC rectangular plates with different edge supports. Several numerical results are provided to reveal the influences of the weight percentage of single-walled and multi-walled CNTs, CNT aspect ratio, volume fraction of fibers, length-to-thickness ratio of plate and boundary conditions on the nonlinear responses of the CNT-FPMLC plates.

  • large deflection geometrically nonlinear analysis of functionally graded multilayer graphene platelet reinforced polymer composite rectangular plates
    Composite Structures, 2017
    Co-Authors: R Gholami, R Ansari
    Abstract:

    Abstract A large deflection geometrically nonlinear analysis of functionally graded (FG) multilayer graphene platelet-reinforced polymer composite (GPL-RPC) rectangular plates subjected to uniform and sinusoidal transverse mechanical loadings is performed in this article. Based on the sinusoidal shear deformation plate theory and von Karman nonlinear strain-displacement relations, the nonlinear governing equilibrium equations and boundary conditions are developed by using the principle of virtual work. It is assumed that the weight fraction of GPL nanofillers layer-wisely changes across the thickness of plate. The effective Young’s modulus of FG-GPL-RPCs is approximately calculated via the modified Halpin-Tsai model. Also, the effective Poisson’s ratio and mass density are determined by employing the rule of mixture. The investigation is performed by using a numerical solution approach. To evaluate the nonlinear bending stiffness of FG multilayer GPL-RPC plate, the discretization of governing equations and boundary conditions is carried out using the generalized differential quadrature (GDQ) method, and the pseudo arc-length continuation technique is employed to solve the set of nonlinear algebraic discretized equations to obtain the Load-Deflection Curve. Numerical problems are given to reveal the influences of GPL distribution pattern, weight fraction, geometry of GPL nanofillers, length-to-thickness and edge conditions on nonlinear bending responses of the GPL-RPC plates.

Tongfei Shi - One of the best experts on this subject based on the ideXlab platform.

  • experimental study on mechanical properties and fracture toughness of magnesium phosphate cement
    Construction and Building Materials, 2015
    Co-Authors: Tongfei Shi
    Abstract:

    Abstract The mechanical properties and fracture toughness of magnesium phosphate cement (MPC) were studied in this paper. The results show that the strengths (compressive, flexural, axial tensile and splitting strengths) of MPC increased rapidly over curing ages and then increasing rates slowed down. The compressive strength increased with the addition of fly ash, while the tensile strength decreased. For both the specimens with and without the addition of fly ash, the axial tensile strength was lower than the splitting strength. The axial tensile strength of MPC without fly ash was 1/13–1/10 of compressive strength and the axial tensile strength of MPC with fly ash is 1/17–1/14 of compressive strength. The ratio decreased over time. The load–deflection Curve showed the failure mode of MPC is brittle failure. The fracture energy increased over time, while the value was relatively small. The failure load and the corresponding mid-span deflection of MPC decreased in presence of fly ash, which results in the further decrease of fracture energy of MPC.

Manu Santhanam - One of the best experts on this subject based on the ideXlab platform.

  • mechanical properties of high strength concrete reinforced with metallic and non metallic fibres
    Cement & Concrete Composites, 2007
    Co-Authors: A Sivakumar, Manu Santhanam
    Abstract:

    Abstract This paper focuses on the experimental investigation carried out on high strength concrete reinforced with hybrid fibres (combination of hooked steel and a non-metallic fibre) up to a volume fraction of 0.5%. The mechanical properties, namely, compressive strength, split tensile strength, flexural strength and flexural toughness were studied for concrete prepared using different hybrid fibre combinations – steel–polypropylene, steel–polyester and steel–glass. The flexural properties were studied using four point bending tests on beam specimens as per Japanese Concrete Institute (JCI) recommendations. Fibre addition was seen to enhance the pre-peak as well as post-peak region of the load–deflection Curve, causing an increase in flexural strength and toughness, respectively. Addition of steel fibres generally contributed towards the energy absorbing mechanism (bridging action) whereas, the non-metallic fibres resulted in delaying the formation of micro-cracks. Compared to other hybrid fibre reinforced concretes, the flexural toughness of steel–polypropylene hybrid fibre concretes was comparable to steel fibre concrete. Increased fibre availability in the hybrid fibre systems (due to the lower densities of non-metallic fibres), in addition to the ability of non-metallic fibres to bridge smaller micro cracks, are suggested as the reasons for the enhancement in mechanical properties.