Mechanical integrity of PEEK bone plate in internal fixation of femur: experimental and finite element analysis towards performance measurement

Even though Finite Element Analysis (FEA) is considered to be an accurate static and dynamic simulation method, it is used only to verify the Mechanical Integrity (MI) of Steam Turbine (ST) blades, due to the time required to set up and perform a typical FEA. Furthermore, the complexity of the blade model results in convergence issues that further increase the analysis time, which can last several days. Instead, faster, lower order empirical tools with increased conservatism are preferred for the design phase. Based on parametric steam turbine blades definition, the Mechanical Integrity and Design Analysis Suite (MIDAS) provides a platform for rapid, fully-automated 3D model generation and FEA. The analysis applies simplified contact interactions on a fully structured mesh, aiming primarily for model convergence in a short time, whilst maintaining the required accuracy. In order to verify that, an extended comparison of MIDAS static and vibrational analysis results with the state-of-the-art FEA and experimental measurements is performed. Therefore, with MIDAS an accurate full FEA is completed within few minutes for each blade, speeding up the MI validation process and enabling its use at the design of every ST blade. Furthermore, the use of FEA contributes to an extended blade application envelope and optimised blade geometry. As a result, MIDAS presents several benefits to new and existing ST customers including increased operational flexibility, extended blade life, faster delivery of the ST cylinders at a lower acquisition cost and extended outage intervals.

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Finite Element Analysis and Comparative Study of 4 Kinds of Internal Fixation Systems for Anterior Cervical Discectomy and Fusion in Children

10.21203/rs.3.rs-1025811/v1 ◽

2021 ◽

Author(s):

ziyu li ◽

Jianqiang Zhou ◽

Zhijun Li ◽

Shaojie Zhang ◽

xing wang ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Cervical Spine ◽

Finite Element Model ◽

Internal Fixation ◽

Element Model ◽

Lower Cervical Spine ◽

Element Analysis ◽

Internal Fixation System ◽

Fixation System

Abstract Background: Spinal injury in children usually occurs in the cervical spine region. Anterior fixation of lower cervical spine has been applied in the treatment of pediatric cervical spine injury and disease due to its stable and firm mechanical properties. This study performed finite element analysis and comparison of 4 different anterior cervical internal fixation systems for children, and explored more stable methods of anterior cervical internal fixation in children. Methods: A finite element model of 6-year-old children with lower cervical spine C4/5 discectomy was established, and the self-designed lower cervical spine anterior locking internal fixation system ACBLP and the children’s anterior cervical internal fixation system ACOP, ACVLP, ACSLP plate screws were fixed and loaded on the model. 27.42N•m torque load was applied to each internal fixation model under 6 working conditions of anteflexion, backward flexion, left flexion, right flexion, left rotation and right rotation, to simulate the movement of the cervical spine. The activity and stress distribution cloud diagram of each finite element model was obtained. Results: In the four internal fixation models of ACOP, ACVLP, ACSLP, and ACBLP, the mobility of C4/5 segment basically showed a decreasing relationship, and the mobility of adjacent segments increased significantly. In the Mises stress cloud diagram of the cervical spine of the four models, the vertebral body and accessories of the ACBLP model born the least stress, followed by ACSLP; The steel plate and screws in the ACVLP internal fixation model were the most stressed; The stress of the internal fixation system (plate/screw) in all models increased in the order of ACBLP, ACSLP, ACVLP, and ACOP.Conclusions: ACBLP internal fixation system had obvious advantages in anterior internal fixation of lower cervical spine in children, C4/5 had the smallest degree of movement, relative displacement was minimal, the stress on the pedicle was the least while the stress on the plate screw was relatively the smallest.

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