大跨度空间结构对空间非均匀地震激励（如行波效应）敏感，为深入揭示其动力响应机制并评估关键构件参数的影响，以四川省乐山市某跨度67.5m的曲线钢管桁架工程为研究对象，建立了经现场模态验证的精细化有限元模型。综合运用模态分析、反应谱分析及弹性时程分析方法，系统对比了一致输入与行波输入下结构的动力特性、位移及内力响应差异，并量化分析了下弦杆截面参数的敏感性。研究结果表明：(1)行波效应显著改变了响应分布，加剧了位移与内力的非均匀性，导致拱顶、塔顶和塔底等关键位置的峰值位移与内力较一致激励下明显增大；(2)下弦杆直径减小10%导致跨中挠度增加15.2%，并加剧了应力集中，该影响显著大于壁厚调整的影响；(3)行波输入引发了显著时滞与幅值放大效应，且此效应随长周期分量增强而突出。本研究阐明了大跨度曲线桁架在非一致激励下的响应规律与关键构件的控制作用，为同类结构抗震设计提供依据与参数控制策略。

Large-span spatial structures are sensitive to spatially non-uniform seismic excitation (such as traveling wave effects). To gain a deeper understanding of their dynamic response mechanisms and assess the influence of key structural parameters, a refined finite element model validated through on-site modal testing was established using a curved steel tube truss structure with a span of 67.5 m in Leshan City, Sichuan Province, as the research subject. By comprehensively applying modal analysis, response spectrum analysis, and elastic time history analysis methods, the study systematically compared the dynamic characteristics, displacement, and internal force responses of the structure under consistent input and traveling wave input conditions, and quantitatively analyzed the sensitivity of the lower chord member cross-section parameters. The research results indicate: (1)The traveling wave effect significantly alters the response distribution, exacerbating the non-uniformity of displacement and internal forces, resulting in significantly increased peak displacements and internal forces at critical locations such as the arch crown, tower top, and tower base compared to consistent excitation; (2)A 10% reduction in the lower chord diameter increases mid-span deflection by 15.2% and exacerbates stress concentration, with this effect being significantly greater than that of wall thickness adjustments; (3)Traveling wave input induces significant time delay and amplitude amplification effects, which become more pronounced as long-period components strengthen. This study elucidates the response patterns of large-span curved trusses under non-uniform excitation and the control role of key components, providing a basis and parameter control strategies for seismic design of similar structures.