Differenze

Queste sono le differenze tra la revisione selezionata e la versione attuale della pagina.

--- wikifemfuchde2019:lez_2019-05-28 [2019/05/28 06:54] – 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.
+Being "softly" connected to the chassis structure, the driver is considered uncoupled from the vehicle for vibration modes high enough in frequency.
+{{ :wikifemfuchde2019:monocoque_chassis_2019_v006.mud |}}
+Loadcases
+  * 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);
+----
+{{ :wikialtro2018:animacomp.proc | MSC.Mentat procedure for creating poor man harmonic response animations}}
+{{ :wikifemfuchde2019:animamodipropri.proc | MSC.Mentat procedure for creating poor man natural mode animations}}
+----
+[[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]]).
+Added constraints stiffen up the structure, thus increasing natural frequencies.
+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.
+----
+Structural damping references
+{{ :wikipaom2017:structural_damping_values_jdstevenson.pdf |}}
+{{ :wikipaom2017:damping_cross-reference_and_material_properties.pdf |}}
+{{ :wikipaom2017:f_orban_damping_of_materials_and_members_in_structures.pdf |}}
+{{ :wikipaom2017:tom_irvine_damping_in_bolted_and_welded_joints.pdf |}}
+{{ :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.