A simplified finite element model of a human thorax had been developed for probing into the mechani- cal response in simple and complex blast environments. The human thorax model was first created by CT images with bl...A simplified finite element model of a human thorax had been developed for probing into the mechani- cal response in simple and complex blast environments. The human thorax model was first created by CT images with blast loading applied via a coupled arbitrary Lagrangian- Eulerian method, allowing for a variety of loads to be considered. The goal is to analyze the maximum stress distri- butions of lung tissue and peak inward thorax wall velocity and to know the possible regions and levels of lung injury. In parallel, a mathematical model has been modified from the Lobdell model to investigate the detailed percentage of lung injury at each level. The blast loadings around the human tho- rax were obtained from the finite element model, and were then applied in the mathematical model as the boundary con- ditions to predict the normalized work of the human thorax lung. The present results are found in agreement with the modified Bowen curves and the results predicted by Axels- son＇s model.展开更多
Objective:Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks.Numerical simulation methods investigating the formation of natural fragments and i...Objective:Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks.Numerical simulation methods investigating the formation of natural fragments and injuries to biological targets are expected to be developed.Methods:A cylindrical warhead model was established and the formation process of natural fragments was simulated using the approach of tied nodes with failure through the explicit finite element(FE)software of LS-DYNA.The interaction between the detonation product and the warhead shell was simulated using the fluidestructure interaction algorithm.A method to simulate the injury of natural fragments to a biological target was presented by transforming Lagrange elements into smooth particle hydrodynamics(SPH)particles after the natural fragments were successfully formed.A computational model of the human thorax was established to simulate the injury induced by natural fragments by the node-to-surface contact algorithm with erosion.Results:The discontinuous velocities of the warhead shell at different locations resulted in the formation of natural fragments with different sizes.The velocities of natural fragments increased rapidly at the initial stage and slowly after the warhead shell fractured.The initial velocities of natural fragments at the central part of the warhead shell were the largest,whereas those at both ends of the warhead shell were the smallest.The natural fragments resulted in bullet holes that were of the same shape as that of the fragments but slightly larger in size than the fragments in the human thorax after they penetrated through.Stress waves propagated in the ribs and enhanced the injury to soft tissues;additionally,ballistic pressure waves ahead of the natural fragments were also an injury factor to the soft tissues.Conclusion:The proposed method is effective in simulating the formation of natural fragments and their injury to biological targets.Moreover,this method will be beneficial for simulating the combined injuries of natural fragments and shock waves to biological targets.展开更多
为研究真实工况下人员在爆炸冲击波作用下的动态响应特性,开展某型云爆弹静爆作用下工事内仿人形装置(Anthropomorphic Test Device,ATD)和绵羊的毁伤试验研究。采用爆炸测试装置和简易假人作为研究对象,通过6发爆炸试验分析爆炸冲击波...为研究真实工况下人员在爆炸冲击波作用下的动态响应特性,开展某型云爆弹静爆作用下工事内仿人形装置(Anthropomorphic Test Device,ATD)和绵羊的毁伤试验研究。采用爆炸测试装置和简易假人作为研究对象,通过6发爆炸试验分析爆炸冲击波在ATD表面传播规律,开展2种人员损伤预测模型的对比分析。研究结果表明:在本试验工况下,冲击波和崩落的混凝土碎块是主要的毁伤元;爆炸冲击波在ATD表面首先发生反射,随后绕射至其他部位,压力曲线表现出非典型冲击波特征,反射叠加效应明显;在典型冲击波特征正压作用时间区间内,由于Axelsson损伤模型线性阻尼项的影响,求解的胸壁运动速度呈现出先增大至峰值后降低的现象;Axelsson损伤模型与UFC 3-340-02规范相比,在人员损伤预测方面相对保守。所得研究结果可为工程应用及毁伤评估提供参考。展开更多
研究目的是分析正面冲击载荷条件下,胸腔骨骼结构和软组织结构材料参数的变化对胸部不同碰撞响应参数的影响。采用一个已经建立并验证的人体胸部有限元模型,基于胸腔骨骼和软组织的多个材料参数,进行正面冲击载荷下的胸部碰撞模拟,分别...研究目的是分析正面冲击载荷条件下,胸腔骨骼结构和软组织结构材料参数的变化对胸部不同碰撞响应参数的影响。采用一个已经建立并验证的人体胸部有限元模型,基于胸腔骨骼和软组织的多个材料参数,进行正面冲击载荷下的胸部碰撞模拟,分别输出主要的胸部响应参数值,并采用标准多项式拟合方法详细对比分析了胸部材料参数发生变化时胸腔的不同响应。结果表明胸腔骨骼和软组织材料参数的变化对正面碰撞载荷下胸部碰撞响应的影响程度各不相同。其中,骨骼和软组织材料参数的变化对胸部碰撞力(Fmax)和胸部变形量(Dmax)的影响显著,肋骨骨折数(Number of Rib Fracture,NRF)和T12加速度(Gmax-T12)的影响次之,而材料参数的变化对胸部变形速率(Vmax)和T1加速度(Gmax-T1)的影响较小。同时,Fmax,Dmax,Gmax-T12等参数主要受软组织材料参数的影响,而肋骨骨折数(NRF)则更多受到骨骼材料参数变化的影响。展开更多
文摘A simplified finite element model of a human thorax had been developed for probing into the mechani- cal response in simple and complex blast environments. The human thorax model was first created by CT images with blast loading applied via a coupled arbitrary Lagrangian- Eulerian method, allowing for a variety of loads to be considered. The goal is to analyze the maximum stress distri- butions of lung tissue and peak inward thorax wall velocity and to know the possible regions and levels of lung injury. In parallel, a mathematical model has been modified from the Lobdell model to investigate the detailed percentage of lung injury at each level. The blast loadings around the human tho- rax were obtained from the finite element model, and were then applied in the mathematical model as the boundary con- ditions to predict the normalized work of the human thorax lung. The present results are found in agreement with the modified Bowen curves and the results predicted by Axels- son＇s model.
基金The work was funded by the National Science Foundation for Young Scientists of China(11902356)China Postdoctoral Science Foundation(2018M633715)+1 种基金Innovation and Cultivation Fund of the Sixth Medical Center of PLA General Hospital(No.CXPY201825)the Army Scientific Research(LB20182D040012).
文摘Objective:Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks.Numerical simulation methods investigating the formation of natural fragments and injuries to biological targets are expected to be developed.Methods:A cylindrical warhead model was established and the formation process of natural fragments was simulated using the approach of tied nodes with failure through the explicit finite element(FE)software of LS-DYNA.The interaction between the detonation product and the warhead shell was simulated using the fluidestructure interaction algorithm.A method to simulate the injury of natural fragments to a biological target was presented by transforming Lagrange elements into smooth particle hydrodynamics(SPH)particles after the natural fragments were successfully formed.A computational model of the human thorax was established to simulate the injury induced by natural fragments by the node-to-surface contact algorithm with erosion.Results:The discontinuous velocities of the warhead shell at different locations resulted in the formation of natural fragments with different sizes.The velocities of natural fragments increased rapidly at the initial stage and slowly after the warhead shell fractured.The initial velocities of natural fragments at the central part of the warhead shell were the largest,whereas those at both ends of the warhead shell were the smallest.The natural fragments resulted in bullet holes that were of the same shape as that of the fragments but slightly larger in size than the fragments in the human thorax after they penetrated through.Stress waves propagated in the ribs and enhanced the injury to soft tissues;additionally,ballistic pressure waves ahead of the natural fragments were also an injury factor to the soft tissues.Conclusion:The proposed method is effective in simulating the formation of natural fragments and their injury to biological targets.Moreover,this method will be beneficial for simulating the combined injuries of natural fragments and shock waves to biological targets.
文摘为研究真实工况下人员在爆炸冲击波作用下的动态响应特性,开展某型云爆弹静爆作用下工事内仿人形装置(Anthropomorphic Test Device,ATD)和绵羊的毁伤试验研究。采用爆炸测试装置和简易假人作为研究对象,通过6发爆炸试验分析爆炸冲击波在ATD表面传播规律,开展2种人员损伤预测模型的对比分析。研究结果表明:在本试验工况下,冲击波和崩落的混凝土碎块是主要的毁伤元;爆炸冲击波在ATD表面首先发生反射,随后绕射至其他部位,压力曲线表现出非典型冲击波特征,反射叠加效应明显;在典型冲击波特征正压作用时间区间内,由于Axelsson损伤模型线性阻尼项的影响,求解的胸壁运动速度呈现出先增大至峰值后降低的现象;Axelsson损伤模型与UFC 3-340-02规范相比,在人员损伤预测方面相对保守。所得研究结果可为工程应用及毁伤评估提供参考。
文摘研究目的是分析正面冲击载荷条件下,胸腔骨骼结构和软组织结构材料参数的变化对胸部不同碰撞响应参数的影响。采用一个已经建立并验证的人体胸部有限元模型,基于胸腔骨骼和软组织的多个材料参数,进行正面冲击载荷下的胸部碰撞模拟,分别输出主要的胸部响应参数值,并采用标准多项式拟合方法详细对比分析了胸部材料参数发生变化时胸腔的不同响应。结果表明胸腔骨骼和软组织材料参数的变化对正面碰撞载荷下胸部碰撞响应的影响程度各不相同。其中,骨骼和软组织材料参数的变化对胸部碰撞力(Fmax)和胸部变形量(Dmax)的影响显著,肋骨骨折数(Number of Rib Fracture,NRF)和T12加速度(Gmax-T12)的影响次之,而材料参数的变化对胸部变形速率(Vmax)和T1加速度(Gmax-T1)的影响较小。同时,Fmax,Dmax,Gmax-T12等参数主要受软组织材料参数的影响,而肋骨骨折数(NRF)则更多受到骨骼材料参数变化的影响。
