采用NACA0014翼型设计了一种基于复合材料弹性周期结构和柔性蒙皮的变弦长机翼。根据结构刚度要求引入了预变体概念，在保证结构强度和刚度的前提下实现了非机构性高变弦长能力。避免了传统机构变体结构重量大、驱动复杂的缺点。建立了机翼的有限元模型，基于静强度分析给出了机翼弦向变体最大幅值。建立机翼的气动分析模型，计算了机翼在不同变体状态下的气动性能。根据机翼法向刚度要求完成了预变体分析，并校核了严酷工况和经济巡航工况下机翼结构的强度、刚度和稳定性。通过超载计算预测了结构初始损伤模式和极限载荷系数。开展了固有模态分析和瞬态分析，给出了变体机翼的基本动力学响应。分析表明，基于对称双波纹弹性周期结构设计的变弦长机翼，结构和驱动机构简单，变体时翼面较光顺，强度、刚度和稳定性满足设计要求。弹性周期结构最大伸展量为140 mm，为周期结构初始弦长的58.33%，为机翼原始弦长的23.33%。未变体状态和最大变体状态机翼的最大安全迎角均为12°，有利迎角均为8°。最大变体状态机翼升力比原始状态提高22.89%。预变体伸展量为16 mm时，硅橡胶柔性蒙皮预应力状态即可满足Y向刚度要求。气动载荷增大到静强度载荷1.96倍时，周期结构发生初始损伤，损伤模式为纤维拉伸破坏。最大变体状态一阶和二阶固有模态依次为竖直和水平弯曲振型。平飞中遭遇突风载荷时，变体机翼位移在2 s内基本收敛。

A variable chord wing based on composite material elastic periodic structure and flexible skin is designed using NACA0014 profile. According to the requirement of structure stiffness， the concept of pre-morphing is introduced. The non-mechanical high variable chord length is realized， while ensuring the structure strength and stiffness. The disadvantages of heavy weight and complex drive of traditional morphing mechanism are avoided. A finite element model of the wing is built， and the maximum chord morphing amplitude is given based on static strength analysis. An aerodynamic analysis model of the wing is established， and the aerodynamic performance of the wing is calculated at different morphing states. The pre-morphing analysis is done according to stiffness requirement in the normal direction. The strength， stiffness and stability of the morphing wing structure are checked in the heavy load case and economical cruise case. The initial damage mode and ultimate load factor of the wing structure are predicted through overload calculation. The normal mode analysis and transient analysis of the morphing wing are completed， and the basic dynamic performance is given. It is shown that the variable chord wing based on symmetrical double ripple elastic periodic structure has simple structure and activation mechanism. During chord morphing， the streamline and smooth wing surface are maintained， and the strength， stiffness and stability of the morphing wing meet the design requirements. The maximum stretch amplitude of the elastic periodic structure is 140 mm， which is 58.33% of the initial chord length of periodic structure and 23.33% of the initial wing chord length. The maximum safety angle of attack and the optimum angle of attack of the initial and maximum morphing states of the wing is 12° and 8°， respectively. The lift of the maximum morphing state is higher than that of the initial states by 22.89%. The stiffness issue in Y direction is satisfied through the pre-stressed silicon rubber skin with the pre-chord-morphing of 16 mm. The initial damage of the periodic structure occurs when the aerodynamic load increases up to 1.96 times of the static strength heavy load， and the damage mode is fiber tensile failure. The first and second order normal modes of the maximum morphing state are vertical and horizontal bending， respectively. The displacement kinetic convergence of the morphing wing occurs in 2 s when gust load is encountered during level flight.