Initial model

{{ :wikifemfuchde2019:monocoque_chassis_2019_v000.mud |}}

just before the break model

{{ :wikifemfuchde2019:monocoque_chassis_2019_v001.mud |}}

model at the end of the lesson

{{ :wikifemfuchde2019:monocoque_chassis_2019_v004.mud |}}

==== Properties ====
**Suspension link trusses**

Solid circular beam sections, ø12mm, aluminum. 
Essentially rigid with respect to other chassis structures.

**Rear framework**

Hollow circular section beam, aluminum.

Main structure: outer diameter ø40mm, wall thickness 1.8mm. 

Stiffeners: outer diameter ø30mm, wall thickness 1.2mm. 

**Composite monocoque**

Thicker backbone: 1.8mm aluminum sheet, 25.4mm aluminum honeycomb 3003, density 5.2 lb/ft^3 ({{ :wikifemfuchde2019:hex-3003-td.pdf |}}), 1.8mm aluminum sheet.


Thinner panels: 1.8mm aluminum sheet, 6.75mm same aluminum honeycomb, 1.8mm aluminum sheet.

Frontal shock absorber support plate: provisionally as thinner panels, to be defined based on shock.

**Inertial elements**

{{ :wikifemfuchde2019:monocoque_chassis_2019_inertial_elements_alone.mud |}}

{{ :wikifemfuchde2019:inertially_equivalent_cuboid_engine.ods |}}

{{ :wikifemfuchde2019:inertially_equivalent_cuboid_wheel_assemblies.ods |}}

** Notes: **

The pedagogical model proposed does **not** include sway/antiroll bars, that are instead a critical element for torsional stiffness loadcases.

In particular, torsional stiffness should be evaluated in both the limiting cases of
  * rigid springs, disconnected sway bars;
  * disconnected springs, rigid sway bar.

This second loadcase, which is usually neglected, is however relevant for sizing the sway bar support areas on the chassis structure.

==== Loadcases ====

  * Static test: torsional stiffness;
    * preliminary suspension stroke motion test ({{:wikitelaio2016:telaio_monocoque_comeimportato_tutorial_optistruct.mud|original Optistruct tutorial version}} m( );
    * rigid spring or rigid anti-roll bar?
  * Front, right wheel bump loadcase (inertia relief);
  * Frontal crash absorber collapse loadcase (inertia relief); at the element faces belonging to the ''crash_absorber_bearing_area'' set (an approx. 155x320 mm area at the front bulkhead), a 25 psi = 0,172 MPa distributed pressure is applied which is due to the honeycomb absorber crushing  (see {{ :wikitelaio2017:plascore_crushlite.pdf |datasheet}}).
  * 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);

==== Connectors ====
RBE3 link kinematics. 

{{:wikipaom2015:cinematica_rbe3.png?300|}}

{{:wikipaom2015:cinematica_rbe3_v1.pdf|sorgente ipe}}