钢绞线偏轴应变测量方法及实验研究

Measurement Method and Experimental Study of Prestressed Strand Deflection Axial Strain

研究用电阻应变方法测量预应力钢绞线的有效预拉应力。经过对预应力混凝土结构中预应力钢绞线的轴向应变和表面钢丝方向的(偏轴)应变分析,建立了钢绞线轴向应变和偏轴应变之间的转换关系,用实验验证了转换关系的正确性。需要测量预应力混凝土结构中钢绞线的有效预应力时,只需沿钢绞线表面钢丝轴线方向粘贴应变片,测出钢丝轴线方向应变,就可以很方便地转换为钢绞线轴向应变,求出其预拉应力和预拉力。

Through analyzing the axial tensile stress and its axial strain in the structure of concrete ,and the strain along strand surface, the relationship between the translation of axial strain and deflection axial strain of strand is obtained, and the accuracy of the translation has been proved based on the experiments. It can be very convenient to translate the strand axial strain with attaching gage to the surface of strand, to the axial strain of strand when measuring of availability pretensile stress created in strand in the prestressed concrete structure is needed, and to solute the pretensile stress and pretension force.