Numerical Simulation on Cloud Detonation Shock Wave Loading on Goat Thorax

To investigate the injury effects of cloud detonation shock waves on biological targets, a cloud detonation model and a finite element model of the goat thorax were established. Shock wave pressure-time histories at different locations were obtained through numerical simulation of cloud detonation and were applied as input loads to the external air-domain boundary on the blast-facing side of the goat thoracic model. The interaction process between the shock wave and the goat thorax was simulated using a fluid-structure coupling method between the air domain and thoracic tissue structures. Mesh independence verification was performed for both the cloud detonation model and the goat thoracic finite element model, and model validity was analyzed by comparison with field test results. On this basis, chest wall displacement velocity, thoracic compression process, and stress responses at different lung locations were extracted to investigate the dynamic response of the goat thoracic model under shock wave loading. By varying load parameters, including peak overpressure, impulse, and pressure rise time, the effects of different shock wave parameters on thoracic deformation characteristics and pulmonary stress propagation were analyzed. The applicability of cloud-detonation-induced lung injury evaluation indexes was further assessed by combining the maximum thoracic compression rate criterion with the pulmonary stress criterion. The results show that, under shock wave loading, chest wall motion compresses the lung and induces stress wave propagation within the pulmonary tissue. As impulse and pressure rise time increase, the sustained compression effect of the shock wave on the chest wall is enhanced, while the reflection characteristics of stress waves propagating in the lung are weakened. Therefore, the maximum thoracic compression rate alone cannot fully evaluate lung injury. Using the maximum thoracic compression rate as an evaluation index for lung injury under cloud detonation conditions has certain limitations and may underestimate lung injury severity under high-impulse and long-rise-time loading conditions. Chest compression and the maximum compression rate can be used together as auxiliary criteria for evaluating lung injury under cloud detonation conditions.