Finite Element Model for Local Instantaneous Impact Protection Analysis Based on Digital Arm

Background: This study investigates the damage in human tissue in regions subjected to stress when the human body experiences localized, instantaneous impact loads. Methods: Utilizing 727 images spanning from the shoulder to the fingertip of a digital human model based on Chinese demographics, the geometric details of tissue structures were derived via tissue segmentation, 3D modeling, and reverse engineering. A stress-induced damage model for the human forearm was created using the finite element simulation software, commercial software COMSOL Multiphysics 5.5 in the college edition. By applying an impact load of 6.4×10⁶ N m² to the load surface, a response time of 1×10⁻³ s was determined. Subsequently, the force transmission mechanism was examined when the human forearm was under stress. This approach represents the unique aspect of our patent study. Results: The modeling and analysis revealed that skin, fat, and muscle -being viscoelastic tissues -undergo deformation upon experiencing stress impacts. This deformation aids in dissipating energy. In transient states, the body does not sustain severe damage, and the impact-induced damage to these tissues is relatively minimal. However, if the force duration is prolonged or if the impact load is exceedingly high, exceeding the critical limit of adhesive tissue may result in penetration of the tissue at the stress point. Notably, tissues beyond the direct impact area remain largely unharmed. Conclusion: Damage due to localized, instantaneous impact loads is primarily concentrated on the immediate stress surface, while regions beyond this point incur minimal to no damage. Calculations indicate that, while such impacts can cause penetrating injuries, the resulting wounds are typically small. With prompt medical intervention, these injuries are not debilitating to the human body.