【简答题】CONCORD, N.H.—Torrential rain forced hundreds of people from their homes in parts of New England on Sunday, as water flowed over dams an d washed out roads. The governors of New Hampshire and Massachu...
【单选题】直齿圆柱齿轮主要是进行接触疲劳强度计算和弯曲疲劳强度计算,其强度条件分别为 σ H =Z E Z H Z ε ≤[σ H ] 和 σ F = Y sa Y ε ≤[σ F ] 。其中 [σ H ] 为两齿轮中较小的许用接触应力,与接触疲劳极限有关, [σ F ] 为许用( ),它与其疲劳极限有关。