A MODEL FOR STRUCTURAL RESPONSE TO HYDROGEN COMBUSTION LOADS IN SEVERE ACCIDENTS

The response of structures to different pressure histories from hydrog en combustion is analyzed using the model of a linear undamped oscilla tor. The effective static pressures from a slow deflagration, a fast t urbulent flame, a deflagration-to-detonation transition (DDT) and a st able detonation are calculated as functions of oscillator frequency. T he response of components with a low natural frequency, such as the ou termost shell in a large dry containment, is governed by the long-term pressure after combustion. Detonation peak pressure and impulse are n ot important. For structures with low-frequencies, fast flames have a damage potential very similar to detonations. For the investigated pre ssure loads, the normally reflected detonation provides the bounding e ffective static pressure for oscillators up to 500 Hz. Fully confined DDT events can exceed the detonation load near the transition location for structural frequencies above similar to 40 Hz.