不同应变率下皮质骨压缩力学实验与本构模型

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Study on compressive mechanical tests constitutive models cortical bone under different strain rates

Abstract：Corticalbone，asacriticalcomponent the human skeletalsystem，effectivelydispersesabsorbs external impactforces，protectingtheinternal medullrycavitysurroundingsttissues，organsfromdamage.Inorderto investigate the mechanicalresponsecortical boneunder impactloading，quasi-staticdynamiccompression experiments were conducted on porcinecortical bone at varying strain ratesusing a universal material testing machine a split Hopkinson pressure bar apparatus.The compression deformation characteristics corticalbone were observed by employing ultra-depththree-dimensional microscopydigital imagecorrelationtechnques.Aviscoelasticdmageconstitutivemodel wasapplied to fittheexperimentaldata，themodel parameters weredetermined.Theresultsdemonstratethat the compression process cortical boneischaracterized bythe initiationpropagation microcracksmechanical properties thematerialexhibitsignificantstrain-ratedependence.Theelastic modulus，yieldstress，compresivestrngth increase significantlywith increasingstrainrates.Underquasi-staticloading，thestress-straincurveconsists distinct elastic plasticdeformationstages.Incontrast，underhigh-strain-rate loading，thestress-strainresponseremainspurelyelasticat strains below 0.2% ，but transitions into a highly nonlinear regime with increasing compresson.Notably，no significant plastic deformation ocurs under dynamic loading，revealing pronounced viscoelastic behavior. Comparison between the experimental datatheoreticalcurves fromtheconstitutive modelshows goodagreement，withminimaldeviationsbetweenpredictednd measuredvalues.Themodelaccuratelycaptures thecompressivemechanical behaviorcorticalboneacrossdiferentstrain rates.Thisstudyprovides theoreticalreferences forthe treatment impact-inducedhuman injuries protective designs. Keywords：cortical bone; impulsive load; viscoelastic; strain rate;constitutive model

皮质骨作为人体骨骼的主要组成部分，占骨量的 80% ，分布于长骨两端以及短骨、扁骨和不规则骨的内部，凭借其卓越的抗压能力，能有效承载身体质量和抵御外部冲击[1-2]。（剩余13369字）