In recent paper [5], it is shown that the upper decay rate of global solution of compressible Navier-Stokes(CNS) equations converging to constant equilibrium state (1, 0) when the initial data is large and belongs to H 2 (R 3 ) ∩ L p (R 3 )(p ∈ [1, 2)). Thus, the first result in this paper is devoted to showing that the upper decay rate of the first order spatial derivative converging to zero in H 1 −norm is (1 + t)For the case of p = 1, the lower bound of decay rate for the global solution of CNS equations converging to constant equilibrium state (1, 0) in L 2 −norm is (1 + t) − 3 4 if the initial data satisfies some low frequency assumption additionally. In other words, the optimal decay rate for the global solution of CNS equations converging to constant equilibrium state in L 2 −norm is (1 + t) − 3 4 although the associated initial data is large.compressible Navier-Stokes equations. Matsumura and Nishida [15] first established the global existence with the small initial data in H 3 −framework. Later, Valli [29] and Kawashita [10] obtained the global existence with the small initial data in H 2 −framework. Recently, Huang, Li and Xin [8] proved the global existence and uniqueness of system (1.1) with the density containing vacuum in the condition that the initial energy is small. For further results about the well-posedness, we refer the readers to [4,11] and the references therein.The decay problem has been one of main interests in mathematical fluid dynamics, there are many interesting work has been obtained. The optimal decay rate of strong solution was addressed in whole space firstly by Matsumura and Nishida [16], and the optimal L p (p ≥ 2) decay rate is established by Ponce [19]. The authors obtained the optimal decay rate for Navier-Stokes system with an external potential force in series of papers [2,3,28]. By assuming the initial perturbation is bounded inḢ −s rather than L 1 , Guo and Wang [4] built the time decay rate for the solution of system (1.1) by using a general energy method. It should be emphasized that their method in [4] can be used to many other kinds of equations, such as Boltzmann equation, as well as some related fluid models. Many other results for the decay problem for the isentropic or non-isentropic Navier-Stokes equations, one can refer to [12,14,27,30] and the references therein.However, the most of above decay results are established under the condition that the initial data is a small perturbation of constant equilibrium state. A interesting question is what may happen about the large time behavior of global strong solution with general initial data. Very recently, He, Huang and Wang [5] proved global stability of large solution to the system (1.1). Let us give a short review of their work. By using some techniques about the blow-up criterion come from [7,8,25,26,31], and assuming the density is bounded uniformly in time in C α with α arbitrarily small, that is sup t≥0 ρ(t) C α ≤ M , they obtained uniform-in-time bounds for the global solution. This allows them to improve th...

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This paper proposes a novel cross-shaped column in which steel fibre reinforced concrete (SFRC) is integrated with a highstrength stirrup to enhance its seismic behaviour. An experimental investigation was conducted on eight cross-shaped column specimens subjected to cyclic lateral loading. All of the specimens were evaluated in terms of their cracking patterns, failure modes, hysteresis behaviour, deformation and ductility, strength and stiffness degradation, and energy dissipation performance. The effects of the stirrup strength, stirrup spacing, steel fibre content, and axial load ratio were investigated. The experimental results demonstrated that all of the specimens exhibited flexural failure. The cracked concrete of the specimens with steel fibres could be prevented from spalling. The hysteresis loops of all of the specimens were relatively full without a readily observable pinching phenomenon and the specimens possessed a satisfactory energy dissipation capacity. Compared with the normal specimens, the specimens with high-strength stirrups, close stirrup spacing, and steel fibre exhibited a higher energy dissipation capacity, lateral bearing capacity, displacement ductility, and initial stiffness. However, the ductility rapidly decreased as the axial load ratio increased. Additionally, neither the incorporation of steel fibre nor the reduction of the stirrup spacing or the axial load ratio substantially mitigated the stiffness degradation. Based on the test results, calculation models were proposed for calculating the seismic bending moment capacities of the specimens. The calculated values were in accordance with the test results.