【单选题】4 / 7结构基频f=5 Hzf=5\,\text{Hz}f=5Hz时,冲击系数μ\muμ约为?A0.050.050.05B0.2680.2680.268正确C0.450.450.45D1.31.31.3参考答案B参考解析μ=0.1767ln5−0.0157≈0.268\mu=0.1767\ln5-0.0157\approx0.268μ=0.1767ln5−0.0157≈0.268。