Bar Impact
bar_impactCompute impact stress, wave speed, contact duration, and yield for a bar striking a rigid wall end-on via exact St-Venant solution. Also returns force and rebound velocity.
Instructions
St-Venant bar impact, exact (NO solver): a uniform bar striking a rigid wall
end-on. Face stress σ = ρ·c₀·v₀ with c₀ = √(E/ρ) — mass, area and length cancel,
so only a slower strike or a softer/lighter material lowers it; contact lasts
2L/c₀ and the bar leaves stress-free at the strike speed (restitution 1). Past
the yield velocity v_y = σ_y/(ρ·c₀) the face yields and a bilinear material
(tangent_mpa) caps at σ_y + ρ·c_p·(v₀ − v_y), c_p = √(E_t/ρ). E and ρ from
youngs_gpa/density_kg_m3 or a Materials-DB material (which also supplies
yield). area_mm2 adds force_n. The closed-form twin impact_dynamics_submit is
gated against; also the quick ceiling on what any strike at this speed can do to
this material. Uniaxial-stress (slender bar) theory.
Returns {wave_speed_m_s, stress_mpa, elastic_stress_mpa, force_n, contact_duration_ms, rebound_velocity_m_s, yield_velocity_m_s, plastic, plastic_wave_speed_m_s, fidelity, band_pct, valid_range_ok, warnings, escalate_to}.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| area_mm2 | No | ||
| material | No | ||
| length_mm | Yes | ||
| yield_mpa | No | ||
| youngs_gpa | No | ||
| tangent_mpa | No | ||
| velocity_m_s | Yes | ||
| density_kg_m3 | No |