def spring_torsion_torque_t31(hatch, tors_bar):
    """
    Determine the torque due to the laminated torsion bar

    The ICD for this part also calls for stress limit check
    """
    torque_bar = - tors_bar.tors_stiff * (tors_bar.windup_angle - hatch.angle_range)

    max_stress = ((tors_bar.lam_thick * tors_bar.shear_modulus * tors_bar.windup_angle) /
                  tors_bar.lam_length)
    stress_passed = tors_bar.shear_stress_limit > max_stress

    return torque_bar, stress_passed