接入test_mql端止动机械力

tests/test_test_mql_pnl0001_segment.py

@@ -554,6 +554,30 @@ class TestMqlPn3P4NodeChamberSegmentTests(unittest.TestCase):
         )
         self.assertAlmostEqual(rhs[112], -0.8167936695810917)
 
+    def test_full_state_closure_applies_elastic_endstop_force_to_small_masses(self) -> None:
+        closure = self.system.full_state_closure_from_spec(
+            self.spec,
+            inlet_node_pressure_pa=15.31e6,
+            resistance_boundary_pressure_pa=15.29e6,
+        )
+        state = closure.initial_state_vector()
+        state[113] = 1.0e-3
+
+        rhs = closure.rhs(state)
+        initial_rhs = closure.rhs(closure.initial_state_vector())
+        endstop = closure.mechanical_closure.assembly.elastic_endstops[
+            "elasticendstop_8"
+        ].endstop()
+        expected_contact_force = endstop.contact_force(-1.0, 0.0)
+        mass = closure.mechanical_closure.assembly.masses[
+            "mass_friction_endstops_10"
+        ].mass_kg
+
+        self.assertAlmostEqual(
+            rhs[112],
+            initial_rhs[112] - expected_contact_force / mass,
+        )
+
     def test_simulates_full_132_state_closure(self) -> None:
         solution = self.system.simulate_full_state_from_spec(
             self.spec,