切割
发表于 2025-3-28 17:45:59
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确认
发表于 2025-3-28 21:55:55
Introduction, precise description. The designer of an aircraft, for example, must take account of the stresses which arise from runway roughness or air turbulence, although the imposed displacements or pressures vary with time in a manner which defies analytical description, and which indeed cannot even be known
NICE
发表于 2025-3-28 23:14:40
Description II: Spectral Density,they do not reveal the course of the variation of x with time except through the auto-correlation function R(τ) as a function of time interval τ. We are accustomed in vibration work to think of time variation as measured rather by frequency, and we now consider how we can apply this concept to a ran
pineal-gland
发表于 2025-3-29 04:56:03
Vibration Theory I: Receptance,antity usually has the dimension of length or angle. In a real system there will be inertia forces depending on the second time derivative ẍ, viscous damping forces depending on the velocity ẋ, and restoring forces depending on x. The equation governing the vibration can usually be brought into the
性冷淡
发表于 2025-3-29 10:27:02
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Ondines-curse
发表于 2025-3-29 14:43:04
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jabber
发表于 2025-3-29 15:35:50
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Notify
发表于 2025-3-29 20:13:30
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可用
发表于 2025-3-30 01:20:40
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DEFER
发表于 2025-3-30 04:30:51
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