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wikifemfuchde2019:lez_2019-05-28 [2019/05/28 08:34] – ebertocchi | wikifemfuchde2019:lez_2019-05-28 [2019/05/29 05:32] (versione attuale) – ebertocchi |
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| pseudo FSAE model with inertial elements, but not the driver. |
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| Being "softly" connected to the chassis structure, the driver is considered uncoupled from the vehicle for vibration modes high enough in frequency. |
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| {{ :wikifemfuchde2019:monocoque_chassis_2019_v006.mud |}} |
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| Loadcases |
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| * Dynamic modal response; |
| * Dynamic harmonic response: vertical harmonic load at the front, right wheel, 1-100 Hz range, sampled at 0.25Hz resolution ((100-1)*4+1 = 397 steps); |
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| {{ :wikialtro2018:animacomp.proc | MSC.Mentat procedure for creating poor man harmonic response animations}} |
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| {{ :wikifemfuchde2019:animamodipropri.proc | MSC.Mentat procedure for creating poor man natural mode animations}} |
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| [[https://www.youtube.com/watch?v=-LFLV47VAbI|back view]] [[https://www.youtube.com/watch?v=RihcJR0zvfM|side view]] relevance of (improper) constraints on the dynamic behaviour of a structure. |
| Design is reliable in actual operational conditions ([[https://en.wikipedia.org/wiki/Boeing_CH-47_Chinook|link]]). |
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| Added constraints stiffen up the structure, thus increasing natural frequencies. |
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| However, a 0 Hz rigid body mode natural frequency may rise to a finite value due to added positioning constraints; the associate natural mode may be excited in resonance by dynamic loads. |
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| Structural damping references |
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| {{ :wikipaom2017:structural_damping_values_jdstevenson.pdf |}} |
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| {{ :wikipaom2017:damping_cross-reference_and_material_properties.pdf |}} |
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| {{ :wikipaom2017:f_orban_damping_of_materials_and_members_in_structures.pdf |}} |
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| {{ :wikipaom2017:tom_irvine_damping_in_bolted_and_welded_joints.pdf |}} |
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| {{ :wikipaom2017:estratto_afwal-tr-84-3089v2_dampingvalues.pdf |estratto}} vol. 2, sezione 8 di Soovere, J., and M. L. Drake. Aerospace Structures Technology Damping Design Guide.LOCKHEED-CALIFORNIA CO BURBANK, 1985. |
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