To solve the problem of precision of the current elastic-plastic models in masonry structures and the need for seismic fragility analysis

the equivalent diagonal brace model was introduced into the finite element model of masonry structures. According to the lateral stiffness characteristics of solid wall

window wall

and door wall

the corresponding equivalent diagonal brace width calculation formula was proposed. Based on the equivalent diagonal brace model

the elastic-plastic finite element models of the three types of masonry walls were established and analyzed under low-cycle reciprocating loading. The accuracy and practicability of the models were verified by the test results. On this basis

a typical three-story masonry structure finite element model was established. Following the incremental dynamic analysis method

seismic fragility analysis was carried out by taking the maximum inter-story displacement angle and elastic-plastic energy dissipation difference as damage parameters. The fragility curves of the masonry structure model of transverse wall and that of both longitudinal and transverse walls were compared and analyzed. Results show that the traditional inter-story displacement angle could not fully represent the seismic performance of the longitudinal wall

and the damage parameters based on energy could more accurately reflect the evolution process of structural damage and the performance of the longitudinal wall. The finite element model of masonry structures with appropriate precision should be established according to the needs of fragility evaluation and calculation efficiency.