Pancyprian Appl. Mech. Sci. III cheat sheet
Pancyprian Appl. Mech. Sci. III · Keep the key ideas within reach.
Statics, strength and mechanical transmission
In an ideal planar model: pin has two force components, roller one normal reaction, fixed support two force components and a moment.
I = b·h³/12, W = b·h²/6 for a rectangle
Simply supported beam, central load: M_max = F·L/4
Euler: P_cr = π²EI/L_k², with L_k depending on the end conditions
Planar DOF: G = 3(n−1) − 2j₁ − j₂
For the defined ideal lossless gear pair, speed and torque-magnitude ratios are inverse; losses reduce actual output torque.
Pneumatic and hydraulic model reasoning
p = F/A; 1 bar = 10⁵ Pa; 1 MPa = 10 bar
Q = A·v links flow, area and speed
Retraction force uses the annulus (bore minus rod)
Flow control depends on load and circuit; overrunning-load safety requires a properly engineered load-control system.
Hydraulic and pneumatic performance depends on the specified pressure, fluid, components, losses and operating conditions.
Read ISO 1219 symbols by the number of ports and positions
Thermal Physics
Use kelvin in all gas-law and kinetic-theory calculations
Q = mcΔθ for temperature change; Q = mL for change of state
Mixtures: heat lost by hot bodies = heat gained by cold bodies plus calorimeter
pV = nRT and pV = ⅓Nm⟨c²⟩; mean KE = (3/2)kT
For a fixed amount of an ideal gas, internal energy depends only on temperature
First law: ΔU = Q − W with W defined as work done by the gas
Measurement, feedback, PLC and automation
Sensitivity = Δoutput/Δinput; resolution = smallest detectable change
Closed-loop error compares reference and measurement; integral action can remove appropriate steady-state error only under suitable stability and operating assumptions.
PLC scan: read inputs → run program → update outputs
4–20 mA live zero: (I − 4)/16 of the span
Repeatability ≠ accuracy, resolution ≠ sensitivity
Robot DOF come from its joints; workspace is the reachable volume