为研究装配式部分包裹混凝土(PEC)组合梁的受力性能，完成了12个试件的单向往复荷载试验，研究了剪跨比、混凝土厚度、对拉螺栓设置等对承载性能与变形能力的影响。研究结果表明：随着剪跨比的增大，试件的破坏形态由剪切破坏向弯曲破坏发展；在试验加载后期，部分试件出现腹板两侧混凝土破坏不对称现象，导致试件承受弯矩和剪力的同时，还受到了扭矩的作用；对拉螺栓不但能够提高型钢对混凝土的约束效应，防止受压钢翼缘的局部屈曲，而且能够发挥抗剪连接作用，保证型钢与混凝土的协同工作；对于小剪跨比试件，混凝土厚度对承载力的影响较大；混凝土厚度对正截面受弯承载力的影响则相对较小，因此大剪跨比试件的承载力受混凝土厚度的影响相对较小。根据叠加原理，提出了装配式PEC组合梁的受剪承载力计算公式；根据平截面假定，提出了全截面塑性状态下的装配式PEC组合梁的受弯承载力计算方法。提出了三折线模型，建立了Vm-Mm的归一化关系。

The mechanical behavior of fabricated partially encased composite (PEC) beams was investigated by testing 12 specimens under unidirectional cyclic loads. The main test variables were the shear span ratio, concrete thickness and screw arbors etc. The researching results show that: with the increase of shear span ratio, the failure mode of the specimens changes from shear failure to bending failure. In the later stage of loading, some specimens show asymmetric concrete damage on both sides of the web, which leads to additional torsion on the specimens besides bending and shearing. The screw arbors not only enhance the confining effect of steel on concrete and prevent the local buckling of compressed steel flange, but also play the role of shear connection and ensure the composite action between steel and concrete. The concrete thickness has a great influence on the bearing capacity of specimens with a small shear span ratio, but has only a small effect on specimens with a large shear span ratio as its effect on the flexural capacity of normal section is limited. According to the superposition principle, a formula for calculating the shear capacity of fabricated PEC beams was proposed. On the basis of plane section assumption, a method for calculating the bending capacity of fabricated PEC beams was developed. A three-line model was proposed to reflect the normalized relationship between Vm and Mm.