To achieve a damage-controllable and earthquake-resilient steel frame with more feasible and simple dissipative devices, an innovative steel moment-resisting connection with bolted ductile double T-stub fuses is developed in this work. These T-stubs with appropriate free deformation length in the stems, made of Low-Yield-Point (LYP) steels instead of ordinary steels, simultaneously behave as connectors, bearing elements, and replaceable dissipative fuses that benefit from the inherent excellent ductility, dissipation capacity, and fatigue performance of the LYP materials. The cyclic responses of the connections with LYP T-stubs subjected to different weakening strategies are explored and compared via extensive nonlinear numerical parametric analyses. Subsequently, the influences of the free deformation length and the weakened degree of the T-stub stem on the seismic performance and the structural fuse effect are evaluated. Finally, optimal design suggestions for this connection are proposed, which provide a reference for engineering applications. Analytical results demonstrate that properly designed LYP T-stubs with various weakened parameters can act as structural fuses by dissipating more than 90% of the system energy and concentrating most of the plasticity and damage, which effectively protect the main structural members from damage while being subjected to seismic excitations. Besides, due to low yield strengths, to achieve an identical weakened degree, the T-stubs made of LYP steels are stockier than the ones made of traditional or high-strength steels. This feature is able to avoid serious local buckling of stem plates and significant strength degradation, thus is conducive to the improvement of the ductility. By comprehensively considering the construction advantages, ductility, dissipation capacity, structural fuse performance, and material efficiency, LYP T-stub with a relatively thin stem is a more promising solution. The method of increasing the free deformation length of the stem effectively controls the damage within the LYP T-stubs, adequately improves the effect of structural fuses, and further lowers the required weakened degree; thus, the protection of primary frame members is achieved without excessively reducing the strength of the connection. Nevertheless, the T-stub fuses with overly-large free deformation lengths and thin stem plates tend to buckle substantially, resulting in significant strength deterioration that adversely decreases the ductility of the connections. As a result, an optimal solution with a satisfactory weakened degree and an appropriate free deformation length (α_d = 0.8 and l_e = 1.0 b_ts) is suggested as a good compromise among the material efficiency, dissipation and ductility capacities, and structural fuse performance.

为了通过更可行，更简单的耗散装置来实现可控的，抗震的钢框架，在这项工作中，开发了一种创新的钢制抗力矩连接，该系统采用螺栓连接的延性双T型熔断器进行熔断。这些T型短管在杆中具有适当的自由变形长度，由低屈服点（LYP）钢代替普通钢制成，同时充当连接器，轴承元件和可替换的耗散熔断器，这得益于其固有的出色延展性，耗散性LYP材料的性能和疲劳性能。通过广泛的非线性数值参数分析，探索并比较了采用不同弱化策略的LYP T型短管连接的循环响应。后来，评估了T形短柱的自由变形长度和弱化程度对抗震性能和结构熔断效应的影响。最后，针对该连接提出了最佳的设计建议，为工程应用提供了参考。分析结果表明，经过适当设计的，具有各种弱化参数的LYP T型存根可以通过消耗超过90％的系统能量并集中大部分可塑性和损伤来充当结构熔断器，从而有效地保护主要结构构件免受损坏地震激发。此外，由于屈服强度低，为达到相同的弱化程度，由LYP钢制成的T形管比传统或高强度钢制成的T形管更坚固。该特征能够避免杆板严重的局部弯曲和明显的强度降低，从而有利于延展性的提高。通过综合考虑构造优势，延展性，耗散能力，结构保险丝性能和材料效率，具有相对较薄的杆身的LYP T型短截线管是一种更有希望的解决方案。增加杆的自由变形长度的方法有效地控制了LYP T型短管内的损坏，充分改善了结构熔断器的效果，并进一步降低了所需的弱化程度。因此，在不过度降低连接强度的情况下实现了对主框架构件的保护。尽管如此，自由变形长度过大的T型熔断器和薄的阀杆板往往会明显弯曲，导致强度明显下降，从而不利地降低了连接的延展性。结果，获得了一种具有令人满意的弱化程度和适当的自由变形长度（α _d  = 0.8和升_Ë  = 1.0 b _TS）建议作为材料效率，耗散和延展性之间的能力的良好折衷，和结构熔丝性能。