Research On The Stability And Progressive Collapse Resistance Of Aluminum Alloy Single Layer Latticed Domes With Assembled Hub Joints

As a lightweight,high-strength,corrosion resisting material,aluminum alloy has attracted wide attention.Because of aluminum alloy not being welded easily,there are some joint forms suitable for aluminum alloy single-layer reticulated domes,which still have some shortcomings.In this paper,a new type of assembled hub(AH)joint was proposed.The formulas for calculating the stiffness of the joint were derived.The impact of joint stiffness on the stability and progressive collapse resistance of aluminum alloy single-layer reticulated domes was studied by introducing the stiffness characteristics of the AH joint.ANSYS finite element software was used to study the impact of the AH joint on the stability of aluminum alloy single-layer reticulated domes.An equivalent short beam model was proposed to simulate the out-of-plane bending stiffness,in-plane bending stiffness and axial stiffness of the joint.The impact of the AH joint on buckling modes and bearing capacity of K6 aluminum alloy single-layer reticulated domes were analyzed in detail.Taking the initial imperfection and double nonlinearity into consideration,the impact of joint stiffness,span,rise-span ratio and grid forms on the bearing capacity of aluminum alloy single-layer reticulated domes were parameterized.LS-DYNA explicit dynamic analysis program was used to study the impact of the AH joint on the progressive collapse resistance of aluminum alloy single-layer reticulated domes.Taking the failure of members and joints as initial failure modes,the sensitivity of three grid forms of aluminum alloy single-layer reticulated domes was evaluated by using the progressive collapse load grades.From the point of view of energy,the progressive collapse resistance between reticulated domes with rigid joints and AH joints,between different initial failure modes and between different grid forms were compared.By means of the finite element analysis,the reason why the joint stiffness affects the buckling mode and bearing capacity of aluminum alloy single-layer reticulated domes was explained.The rules of how the span,rise-span ratio and grid forms affect the bearing capacity of aluminum alloy single-layer reticulated domes were summarized.The range of the coefficient of bending stiffness of AH joints,the influence coefficient of bearing capacity and the safety coefficient were obtained.The progressive collapse load grades and distribution rules of three grid forms of aluminum alloy single-layer reticulated domes were determined.According to the critical strain energy of progressive collapse,the progressive collapse resistance of aluminum alloy single-layer reticulated domes under different parameters was evaluated.The relationship between instability failure and progressive collapse of reticulated domes was explained.