本文選題：肝臟 + 動態(tài)力學(xué)性能　； 參考：《力學(xué)學(xué)報(bào)》2017年06期

【摘要】：在交通事故中,腹部器官常因沖擊載荷作用而受到傷害,嚴(yán)重時(shí)甚至危及生命.肝損傷是腹部損傷中最為常見的一種,致死率很高,了解肝臟的動態(tài)力學(xué)性能對于事故中肝臟的損傷評估及防護(hù)設(shè)計(jì)有著重要的意義.從新鮮的豬肝組織中取肝實(shí)質(zhì)部分制作試樣,利用英斯特朗材料試驗(yàn)機(jī)對其進(jìn)行兩種加載率(0.004 s~(-1),0.04 s~(-1))和兩種加載方向(垂直肝臟表面和平行于肝臟表面)的準(zhǔn)靜態(tài)壓縮試驗(yàn),并壓縮至破壞.利用改進(jìn)的分離式霍普金森壓桿(split Hopkinson pressure bar,SHPB)實(shí)驗(yàn)裝置沿平行于肝臟表面方向進(jìn)行三種高應(yīng)變率(1 300 s~(-1),2 400 s~(-1),4 500 s~(-1))的動態(tài)壓縮試驗(yàn).結(jié)果表明:所有應(yīng)變率下的豬肝壓縮應(yīng)力應(yīng)變曲線都呈非線性凹向上特征,初始階段應(yīng)力值很低,應(yīng)變約30%后應(yīng)力幅值顯著增大;準(zhǔn)靜態(tài)壓縮時(shí),兩種應(yīng)變率(0.004 s~(-1),0.04 s~(-1))和兩種加載方向下肝臟組織破壞應(yīng)力和破壞應(yīng)變等力學(xué)性能無顯著不同,平均破壞應(yīng)變?yōu)?8%,平均破壞應(yīng)力為0.45 MPa.高應(yīng)變率下肝臟組織的流動應(yīng)力明顯高于準(zhǔn)靜態(tài)下的流動應(yīng)力,表現(xiàn)出一定的率敏感性.采用Yeoh型超彈性本構(gòu)模型描述豬肝組織準(zhǔn)靜態(tài)力學(xué)性能,基于黏超彈性模型理論,提出了一個(gè)能描述肝臟組織從低應(yīng)變率到高應(yīng)變率范圍力學(xué)性能的率相關(guān)本構(gòu)模型,該模型與實(shí)驗(yàn)結(jié)果有很好的一致性.
[Abstract]:In traffic accidents, abdominal organs are often injured by impact load, and even life-threatening. Liver injury is one of the most common abdominal injuries with high mortality. Understanding the dynamic mechanical properties of the liver is of great significance to the assessment and protection design of liver injury in accidents. Samples of liver parenchyma were taken from fresh porcine liver tissue, and quasi static compression tests were carried out in two loading directions (vertical liver surface and parallel to liver surface) with two loading rates (0.004 s-1) and two directions (vertical liver surface and parallel to liver surface). And compress to destroy. The dynamic compression tests of three kinds of high strain rate (1 300 sm ~ (-1) ~ (-1) C ~ (2 400) sm ~ (- 1) ~ (4 500) sm ~ (-1) have been carried out by using an improved split Hopkinson pressure barb experimental apparatus along the direction parallel to the surface of the liver. The results show that the stress-strain curves of porcine liver at all strain rates show a nonlinear concave upward feature, the initial stress values are very low, the stress amplitude increases significantly after about 30% strain, and the stress amplitude increases significantly under quasi-static compression. There was no significant difference between the two strain rates (0.004 s-1) and two directions of loading, such as failure stress and strain of liver tissue. The average failure strain was 48% and the average failure stress was 0.45 MPA. The flow stress of liver tissue at high strain rate was significantly higher than that at quasi static state, showing a certain rate sensitivity. Yeoh hyperelastic constitutive model was used to describe the quasi-static mechanical properties of porcine liver tissue. Based on the viscohyperelastic model theory, a rate-dependent constitutive model was proposed to describe the mechanical properties of liver tissue from low strain rate to high strain rate. The model is in good agreement with the experimental results.
【作者單位】： 合肥工業(yè)大學(xué)土木與水利工程學(xué)院;中國科學(xué)技術(shù)大學(xué)中國科學(xué)院材料力學(xué)行為和設(shè)計(jì)重點(diǎn)實(shí)驗(yàn)室;
【基金】：國家自然科學(xué)基金(11102206) 合肥工業(yè)大學(xué)博士專項(xiàng)科研基金(J2014HGBZ0178)資助項(xiàng)目
【分類號】：U467.14;U491.3
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本文編號：1870659