Impact-induced traumatic brain injury (TBI) is a major source of disability and mortality. Knowledge of brain strains during impact (accelerative) loading is critical for the overall management of TBI, including the development of injury thresholds, personal protective equipment, and validation of computational models. Despite these needs, the current understanding of brain strains in humans or humanlike surrogates is limited, especially for injury causing loading magnitudes. Toward this end, we measured full-field, in-plane (2D) strains in a brain simulant using the hemispherical head surrogate. The hemispherical head was mounted on the Hybrid-III neck and subjected to impact loading using a linear impactor system. The resulting head kinematics was measured using a triaxial accelerometer and angular rate sensors. Dynamic, 2D strains in a brain simulant were obtained using high-speed imaging and digital image correlation. Concurrent finite element (FE) simulations of the experiment were also performed to gain additional insights. The role of stiff membranes of the head was also studied using experiments. Our results suggest that rotational modes dominate the response of the brain simulant. The wave propagation in the brain simulant as a result of impact has a timescale of ~100 ms. We obtain peak strains of ~20%, ~40%, ~60% for peak rotational accelerations of ~838, ~5170, ~11,860 rad/s², respectively. Further, peak strains in cortical regions are higher than subcortical regions by up to ~70%. The agreement between the experiments and FE simulations is reasonable in terms of spatiotemporal evolution of strain pattern and peak strain magnitudes. Experiments with the addition of falx and tentorium indicate significant strain concentration (up to 115%) in the brain simulant near the interface of falx or tentorium and brain simulant. Overall, this work provides important insights into the biomechanics of strain in the brain simulant during impact loading.

撞击引起的创伤性脑损伤 (TBI) 是致残和死亡的主要来源。了解冲击（加速）负荷期间的脑应变对于 TBI 的整体管理至关重要，包括损伤阈值的开发、个人防护设备和计算模型的验证。尽管有这些需求，但目前对人类或类人替代物的脑应变的理解是有限的，特别是对于导致负荷量级的伤害。为此，我们使用半球形头部替代物测量了大脑模拟物中的全场、平面内 (2D) 应变。半球形头安装在 Hybrid-III 颈部并使用线性冲击器系统承受冲击载荷。使用三轴加速度计和角速率传感器测量产生的头部运动学。动态的，使用高速成像和数字图像相关性获得大脑模拟物中的 2D 应变。还进行了实验的并发有限元 (FE) 模拟以获得更多见解。还使用实验研究了头部僵硬膜的作用。我们的研究结果表明，旋转模式主导大脑模拟物的反应。由于撞击而在大脑模拟物中的波传播具有约 100 毫秒的时间尺度。对于~838、~5170、~11,860 rad/s 的峰值旋转加速度，我们获得了~20%、~40%、~60% 的峰值应变 我们的研究结果表明，旋转模式主导大脑模拟物的反应。由于撞击而在大脑模拟物中的波传播具有约 100 毫秒的时间尺度。对于~838、~5170、~11,860 rad/s 的峰值旋转加速度，我们获得了~20%、~40%、~60% 的峰值应变 我们的研究结果表明，旋转模式主导大脑模拟物的反应。由于撞击而在大脑模拟物中的波传播具有约 100 毫秒的时间尺度。对于~838、~5170、~11,860 rad/s 的峰值旋转加速度，我们获得了~20%、~40%、~60% 的峰值应变²，分别。此外，皮质区域的峰值应变比皮质下区域高出约 70%。就应变模式的时空演变和峰值应变幅度而言，实验和有限元模拟之间的一致性是合理的。添加镰刀和小脑幕的实验表明，在镰刀或小脑幕和大脑模拟物界面附近的大脑模拟物中有显着的应变浓度（高达 115%）。总体而言，这项工作为冲击载荷期间大脑模拟物的应变生物力学提供了重要的见解。