• 2022-07-25
    设悬臂梁的密度为\(\rho \),抗弯刚度为\(EI\),其在自由端下面带有刚度系数为\(k\)的弹性支承,系统的频率方程为(定义:\(β^2=\cfrac{ω}{a}, a^2=\cfrac{EI}{ρ}\))
    A: \(\cfrac{k}{EI}=β^3\cfrac{1+\cosh{βl}\cos{βl}}{\cosh{βl}\sin{βl}-\sinh{βl}\cos{βl}}\)
    B: \(-\cfrac{k}{EI}=β^3\cfrac{1+\cosh{βl}\cos{βl}}{\cosh{βl}\sin{βl}-\sinh{βl}\cos{βl}}\)
    C: \(\cfrac{k}{EI}=β^3\cfrac{1+\cosh{βl}\cos{βl}}{\cosh{βl}\sin{βl}+\sinh{βl}\cos{βl}}\)
    D: \(-\cfrac{k}{EI}=β^3\cfrac{1+\cosh{βl}\cos{βl}}{\cosh{βl}\sin{βl}+\sinh{βl}\cos{βl}}\)