液压胀管力的计算与实现

液压胀管法是当今管子与管板连接的新技术,国外对其机型保密。一重集团公司为满足换热器生产需要,经液压胀管力的认真计算,选用国产元件自制了液压胀管机。本文阐述了液压胀管力的计算过程及其实现方法。

液压胀管力的计算及胀管工艺要点

运用Mises屈服准则,科学的计算出液压胀接所需胀管力的大小区间,综合考虑材料、加工精度、设备能力等因素,确定合理的胀管工艺参数。

Expansion performance and self-stressing behavior of CFST columns considering concrete creep and shrinkage effect

Expansive concrete is used in the steel tube of Concrete-filled steel tubular(CFST)columns to solve the problem of steel-to-concrete debonding.Self-stress is generated between concrete and steel plate due to concrete expansion,which can effectively improve the mechanical performance of CFST columns.Deformation tests were conducted on concrete and CFST columns,respectively.The free deformation of concrete and circumferential deformation of steel tubes were measured and analyzed.A calculation method was proposed to evaluate the hoop strain,self-stress and creep deformation of the CFST columns.The test and calculation results indicate that the proper addition of expansion agent in the internal concrete can keep concrete expansive and generate self-stresses for a long time.The expansion and self-stresses prevent the debonding between the steel tube and the internal concrete.Increasing the dosage of expansive agents and reducing the curing age both increase the expansive deformation and self-stress of CFST columns.Increasing the tube thickness reduces the expansive deformation and increases the initial self-stress of CFST columns.