发表机构
Institute of Communication and Computer Systems (ICCS); University of Exeter（通信与计算机系统研究所; 埃克塞特大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对加筋铝翼盒壁板，通过有限元建模和校准，研究了连接非线性对响应的影响，并提出了减基需满足的准则：必须保留连接间的接受度，否则会严重高估硬化效应。
AI 中文摘要
一个加筋铝翼盒壁板的壳有限元模型，该壁板是多个实验研究共用的实验室结构，在其78个物理紧固件位置处建立了板与加强筋之间的连接，并根据实测模态数据进行了校准。通过六参数灵敏度更新子结构模量（变化范围在±20%以内），复现了前五阶实测模态，误差为1.1%–4.3%，模态置信度为0.88–1.00。在网格、质量和阻尼相同的情况下，使紧固件变为非线性，结果表明连接非线性以强烈的不对称方式进入响应。硬化效应几乎不可见，频率最多增加+1%；而软化或滑移连接使前三阶共振频率分别移动-2.1%、-4.9%和-9.2%，摩擦使共振峰值在恢复前最多降低80%。对所有18,804个自由度进行Newmark积分，以及精确凝聚到连接处并沿弧长继续的谐波平衡法，两者一致到5.5×10⁻⁴。随后，基于投影的非线性模型降阶确定了连接结构对减基施加的准则。关键量不是线性响应（11个向量可将其复现到优于0.01%），而是结构在连接之间的 receptance（接受度），126个全局特征向量仅携带约2%的该量；缺少该量时，降阶模型将基频的硬化位移高估了三十倍，并返回一个超出壁板刚性连接极限的值。
英文摘要
A shell finite-element model of a stiffened aluminium wingbox panel, a laboratory structure shared by several experimental studies, is built with its plate-to-stiffener joints at the $78$ physical fastener positions and calibrated against measured modal data, a six-parameter sensitivity update of the substructure moduli within $\pm20\%$ reproducing the first five measured modes to $1.1$--$4.3\%$ with modal-assurance values of $0.88$--$1.00$. Making the fasteners nonlinear, at equal mesh, mass and damping, shows that joint nonlinearity enters the response strongly asymmetrically. Hardening is almost invisible, at most $+1\%$ in frequency, whereas softening or slipping the joints moves the first three resonances by $-2.1$, $-4.9$ and $-9.2\%$, and friction removes up to $80\%$ of the resonant peak before it recovers. Newmark integration of all $18{,}804$ degrees of freedom and a harmonic balance condensed exactly onto the joints and continued in arclength agree to $5.5\times10^{-4}$. A projection-based nonlinear model order reduction then locates the criterion that a jointed structure imposes on a reduced basis. The binding quantity is not the linear response, which eleven vectors reproduce to better than $0.01\%$, but the receptance of the structure between the joints, of which $126$ global eigenvectors carry about $2\%$, and without which the reduced model overpredicts the hardening shift of the fundamental by a factor of thirty and returns a value beyond the rigid-joint limit of the panel.
Comments20 pages, 14 figures
