English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Traumatic brain injury (TBI) occurs when local mechanical load exceedscertain tolerance levels for brain tissue. Extensive research has been donepreviously for brain matter experiencing compression at quasistatic loading;however, limited data is available to model TBI under dynamic impactconditions. In this research, an experimental setup was developed to performunconfined compression tests and stress relaxation tests at strain rates <90/s. The brain tissue showed a stiffer response with increasing strain rates,showing that hyperelastic models are not adequate. Specifically, thecompressive nominal stress at 30% strain was 8.83 +/- 1.94, 12.8 +/- 3.10 and16.0 +/- 1.41 kPa (mean +/- SD) at strain rates of 30, 60 and 90/s,respectively. Relaxation tests were also conducted at 10%-50% strain with theaverage rise time of 10 ms, which can be used to derive time dependentparameters. Numerical simulations were performed using one-term Ogden modelwith initial shear modulus mu_0 = 6.06 +/- 1.44, 9.44 +/- 2.427 and 12.64 +/-1.227 kPa (mean +/- SD) at strain rates of 30, 60 and 90/s, respectively. Aseparate set of bonded and lubricated tests were also performed under the sametest conditions to estimate the friction coefficient mu, by adopting combinedexperimental - computational approach. The values of mu were 0.1 +/- 0.03 and0.15 +/- 0.07 (mean +/- SD) at 30 and 90/s strain rates, respectively,indicating that pure slip conditions cannot be achieved in unconfinedcompression tests even under fully lubricated test conditions. The materialparameters obtained in this study will help to develop biofidelic human brainfinite element models, which can subsequently be used to predict brain injuriesunder impact conditions.

Mechanical Characterization of Brain Tissue in Compression at Dynamic Strain Rates