Stress Analysis of Lumbar Spine

i)A hyperelastic non-linear finite element model of the healthy L4-L5 spine segment was employed.                                     ii).this model has complex component such as ligments & intervertebal disc,annolus,nucleus,facet joint.                               iii).estimating mechanical response of invtrovertebial disc behaviour& is really important to assess degration of the disc based on daily routine dynamic behaviour. iv) in order to assess intervertbral disc,elastic hyperelastic ,porous material can be used to simulate dynamic behaviour.in this case,hyperelastic material is used for annolous &nucleous. v)these contour results shows the dynamic behaviour order lateral bending situation.        vi) one of the purpose of this analysis is to evaluate contact stress of the facet joint. vii)orphan mesh was generated from 3DCAD model which was created based on mr data. viii)it is consisted of 20 components same of 3d parts to represent liagments. ix)Every individual component was defined as individual set.we can see them here. x)generally ,elastic properties are used for the spinal components liagments based on liable papers.no compression ratio was applaied to liagments properties. xi)basically ,ABAQUS supports 8 type of hyperelastic material mooney-riuilin material was used here for anndus ground substance & nucleus pulpous. xii)ts has quasi-transient step to simulate dynamic lateral ,there are many constraints which were used to define the relation between components. xiii)this kinematic coupling created for loading point. xiv)in order to apply axial load as flow two reference points were each point connected to corficial sheel by means of beam type MPC constraints. xv)this is fixed condition for bottom so face of L5.actually used key 0 for lateral bending 7.5n-m was applied on RF-2 & axial load 500N estimatedly human upper-body force was applied on axial connector.