scholarly journals Biomechanics of Lumbar Spine Injury in Road Barrier Collision–Finite Element Study

2021 ◽  
Vol 9 ◽  
Author(s):  
L. Pachocki ◽  
K. Daszkiewicz ◽  
P. Łuczkiewicz ◽  
W. Witkowski
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Bending Moment ◽  
Longitudinal Force ◽  
Spine Injury ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Axial Forces ◽  
Spine Kinematics ◽  
Spine Model

Literature and field data from CIREN database have shown that lumbar spine injuries occur during car crashes. There are multiple hypotheses regarding how they occur; however, there is no biomechanical explanation for these injuries during collisions with road safety barriers (RSBs). Therefore, the objective of this study was to investigate the mechanics of vertebral fractures during car collisions with concrete RSBs. The finite element method was used for the numerical simulations. The global model of the car collision with the concrete RSB was created. The lumbar spine kinematics were extracted from the global simulation and then applied as boundary conditions to the detailed lumbar spine model. The results showed that during the collision, the occupant was elevated, and then dropped during the vehicle landing. This resulted in axial compression forces 2.6 kN with flexion bending moments 34.7 and 37.8 Nm in the L2 and L3 vertebrae. It was shown that the bending moment is the result of the longitudinal force on the eccentricity. The lumbar spine index for the L1–L5 section was 2.80, thus indicating a lumbar spine fracture. The minimum principal strain criterion of 7.4% and damage variable indicated L2 and L3 vertebrae and the inferior part of L1, as those potentially prone to fracture. This study found that lumbar spine fractures could occur as a consequence of vehicle landing during a collision with a concrete RSB mostly affecting the L1–L3 lumbar spine section. The fracture was caused by a combination of axial forces and flexion bending moments.

scholarly journals Bending Moment Calculations for Piles Based on the Finite Element Method

2013 ◽  
Vol 2013 ◽  
pp. 1-19 ◽  
Author(s):  
Yu-xin Jie ◽  
Hui-na Yuan ◽  
Hou-de Zhou ◽  
Yu-zhen Yu
Keyword(s):  
Finite Element ◽  
Computational Methods ◽  
Bending Moment ◽  
Bending Moments ◽  
Sheet Pile ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Passive Pile ◽  
Sheet Pile Wall

Using the finite element analysis program ABAQUS, a series of calculations on a cantilever beam, pile, and sheet pile wall were made to investigate the bending moment computational methods. The analyses demonstrated that the shear locking is not significant for the passive pile embedded in soil. Therefore, higher-order elements are not always necessary in the computation. The number of grids across the pile section is important for bending moment calculated with stress and less significant for that calculated with displacement. Although computing bending moment with displacement requires fewer grid numbers across the pile section, it sometimes results in variation of the results. For displacement calculation, a pile row can be suitably represented by an equivalent sheet pile wall, whereas the resulting bending moments may be different. Calculated results of bending moment may differ greatly with different grid partitions and computational methods. Therefore, a comparison of results is necessary when performing the analysis.

Biomechanical in Vitro and Finite Element Study On Different Sagittal Alignment Postures of the Lumbar Spine During Multiaxial Daily Motion

2021 ◽  
Author(s):  
Nadja Wilmanns ◽  
Agnes Beckmann ◽  
Luis Fernando Nicolini ◽  
Christian Herren ◽  
Rolf Sobottke ◽  
...  
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Planning Process ◽  
Axial Rotation ◽  
Intervertebral Discs ◽  
Fe Model ◽  
Bending Moments ◽  
Sagittal Spinal Alignment ◽  
Biomechanical Response

Abstract Lumbar Lordotic correction (LLC), the gold standard treatment for Sagittal Spinal malalignment (SMA), and its effect on sagittal balance have been critically discussed in recent studies. This paper assesses the biomechanical response of the spinal components to LLC as an additional factor for the evaluation of LLC. Human lumbar spines (L2L5) were loaded with combined bending moments in Flexion (Flex)/Extension (Ex) or Lateral Bending (LatBend) and Axial Rotation (AxRot) in a physiological environment. We examined the dependency of AxRot range of motion (RoM) on the applied bending moment. The results were used to validate a Finite Element (FE) model of the lumbar spine. With this model, the biomechanical response of the intervertebral discs (IVD) and facet joints under daily motion was studied for different sagittal spinal alignment (SA) postures, simulated by a motion in Flex/Ex direction. Applied bending moments decreased AxRot RoM significantly (all P<0.001). A stronger decline of AxRot RoM for Ex than for Flex direction was observed (all P<0.0001). Our simulated results largely agreed with the experimental data (all R2>0.79). During daily motion, the IVD was loaded higher with increasing lumbar lordosis (LL) for all evaluated values at L2L3 and L3L4 and posterior Annulus Stress (AS) at L4L5 (all P<0.0476). The results of this study indicate that LLC with large extensions of LL may not always be advantageous regarding the biomechanical loading of the IVD. This finding may be used to improve the planning process of LLC treatments.

Analysis by the mixed method of statically indeterminate frames with elements of increased rigidity and numerical verification of the calculation results using the finite element method

2021 ◽  
Vol 14 (2) ◽  
pp. 54-66
Author(s):  
Svetlana Sazonova ◽  
Viktor Asminin ◽  
Alla Zvyaginceva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Initial Data ◽  
Mixed Method ◽  
Numerical Verification ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Internal Forces ◽  
Element Method

The sequence of application of the mixed method for calculating internal forces in statically indeterminate frames with elements of increased rigidity is given. The main system is chosen for the frame with one kinematic and one force unknown. The canonical equations of the mixed method are written, taking into account their meaning. Completed the construction of the final diagram of the bending moments and all the necessary calculations and checks. When calculating integrals, Vereshchagin's rule is applied. The solution of the problem is checked by performing the calculation using the computer program STAB12.EXE; the results of the calculations are numerically verified using the finite element method. An example of the formation of the initial data for the STAB12.EXE program and the subsequent processing of the calculation results, the rules for comparing the numerical results and the results obtained in the calculation of the frame by the mixed method are given.

A FEM Model Analysis of Human Lumbar Spine With Bi-Level Artificial Disc Replacement

2006 ◽  
Author(s):  
A. Faizan ◽  
A. Kiapour ◽  
V. K. Goel ◽  
A. Ivanov ◽  
A. Biyani ◽  
...  
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Bending Moment ◽  
Element Model ◽  
Good Alternative ◽  
Disc Replacement ◽  
Artificial Disc ◽  
Fem Model ◽  
Artificial Disc Replacement ◽  
Human Lumbar Spine

A finite element model of human lumbar spine (L3-S1 segment) was used to analyze biomechanical effects of the bi-level CHARITE artificial disc replacement (2LCHD) at L4-L5 and L5-S1 levels. The mechanical behavior and range of motion in implanted and intact models were compared using the finite element analyses and a hybrid loading protocol. In 2LCHD model the changes at L3-L4 level decreased by 25% also the model showed smooth changes in motion at implanted levels. In flexion there was an increase in facet loads at lower levels of 2LCHD however the bending moment in this model was less than intact model because of hybrid loading; in contrast, the facet loads in implanted model decreased in extension. It was observed that the bi-level disc replacement won’t affect much the kinematics of the spine and can be proposed as a good alternative for treatment in cases that disc degeneration occurs at more than one level of spine.

scholarly journals Determining internal forces in modular building elements under action wind load

2018 ◽  
Vol 196 ◽  
pp. 02010
Author(s):  
Viacheslav Shirokov ◽  
Alexey Soloviev ◽  
Tatiana Gordeeva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
Dynamic Characteristics ◽  
Wind Load ◽  
Wind Loads ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Internal Forces

The research paper focuses on internal forces determination in the elements of modular buildings under wind load. It provides a methodology for determining dynamic characteristics of a building and for calculating wind loads. This method is based on the following assumptions: coupling of the modules elements is rigid; coupling of block-modules with foundations is hinged-fixed; connection of blocks to each other is hinged in angular points; the floor disk in its plane is not deformed. On the basis of these assumptions the authors derived approximate and refined equations for determining forces in modules elements under static and pulsation components of wind load. The equation of bending moments determination in the pillar bearing cross-section is obtained by approximation of the graph of moments variation, calculated for the spectrum of the ratio of the pillar stiffness and the floor beam in the range from 1/64 to 64. The paper further introduces the calculation results of forces based on the proposed methodology and on the finite element method. The calculations were done while taking different values of wind load and different number of storeys in a building (from 1 to 4 floors). The obtained results are similar, the error does not exceed 5%.

Analytical Computational Models for Relationship between Ultimate Bending Moment of Concrete Segments and Axial Force

2020 ◽  
Vol 853 ◽  
pp. 177-181
Author(s):  
Zhi Yun Wang ◽  
Shou Ju Li
Keyword(s):  
Numerical Simulation ◽  
Computational Model ◽  
Axial Force ◽  
Computational Models ◽  
Plane Deformation ◽  
Bending Moment ◽  
Analytical Models ◽  
Bending Moments ◽  
Axial Forces ◽  
Practical Engineering

Concrete segments are widely used to support soil and water loadings in shield-excavated tunnels. Concrete segments burden simultaneously to the loadings of bending moments and axial forces. Based on plane deformation assumption of material mechanics, in which plane section before bending remains plane after bending, ultimate bending moment model is proposed to compute ultimate bearing capacity of concrete segments. Ultimate bending moments of concrete segments computed by analytical models agree well with numerical simulation results by FEM. The accuracy of proposed analytical computational model for ultimate bending moment of concrete segments is numerically verified. The analytical computational model and numerical simulation for a practical engineering case indicate that the ultimate bending moment of concrete segments increases with increase of axial force on concrete segment in the case of large eccentricity compressive state.

Geometric and Material Property Study of the Human Lumbar Spine Using the Finite Element Method

1992 ◽  
Vol 5 (4) ◽  
pp. 50-59 ◽  
Author(s):  
W. Suwito ◽  
T. S. Keller ◽  
P. K. Basu ◽  
A. M. Weisberger ◽  
A. M. Strauss ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Lumbar Spine ◽  
Material Property ◽  
The Finite Element Method ◽  
Human Lumbar Spine ◽  
Element Method

scholarly journals ANALYSIS OF THE COMBINED STRUCTURE OF THE SHAFT OF THE DNIPRO METRO BY THE FINITE ELEMENTS METHOD

2021 ◽  
pp. 79-85
Author(s):  
O. L. TIUTKIN ◽  
D. O. BANNIKOV ◽  
V. А. MIROSHNYK ◽  
I. V. HELETIUK
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Models ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Normal Forces ◽  
Combined Design ◽  
Combined Structure ◽  
Design Solutions ◽  
Element Method

Purpose. The development of construction of underground excavations of the Dnipro Metro requires analysis and scientific substantiation of design solutions based on technologies that are new for Ukraine. The aim of the scientific article is to analyze the combined design of the shaft of the Dnipro Metro by the finite element method with determination of force factors in the linings of the pile system and shotcrete system with further substantiation based on the results of design solutions to the real situation of Dnipro Metro construction. Methodology. Two finite element models were constructed for the analysis of the shaft № 1 of the Dnipro Metro by the finite element method. They reflect the combined design of the shaft, which consists of two parts. The finite-element model of the pile system, which reflects the shell of bored piles, supported by a cap beam and ring beams, is analyzed separately. The model for the shotcrete system, which is used for the second part of the shaft, which lies in a solid rock mass, is separately modeled and analyzed. Finite-element models of both systems are assigned real deformation and geometric parameters, as well as the load, which became the key to adequate calculations by the finite element method. Findings. During the numerical analysis of the combined structure of the shaft № 1 of Dnipro Metro, the force factors (normal forces and bending moments) for the pile system and the shotcrete system were determined. These results became the basis for the reinforcement of both systems. Originality. A numerical analysis of the shaft structure was performed, which provided a complete picture of the force factors that allow predicting the appearance of normal forces and bending moments in similar engineering and geological conditions. Practical value. The results of the analysis of the combined design of the shaft of the Dnipro Metro by the finite element method allowed to scientifically substantiate the design solutions and ensure high performance of both shaft systems № 1.

scholarly journals Perencanaan Perencanaan Sruktur Jembatan Lengkung Pada Sungai Sombe-Lewara

2020 ◽  
Vol 4 (2) ◽  
pp. 14-25
Author(s):  
Atur P. N. Siregar ◽  
Anwar Dolu ◽  
M Z H Ragalutu
Keyword(s):  
Structural Analysis ◽  
Bending Moment ◽  
Bending Moments ◽  
Long Span Bridges ◽  
Community Needs ◽  
Final Project ◽  
Long Span ◽  
Axial Forces ◽  
Bridge Type ◽  
Reinforcement Design

Kecamatan Kinovaro secara geografis memiliki banyak sungai yang panjang dan lebar yang menjadi kendala dalam proses pemenuhan kebutuhan masyarakat dan perkembangan daerah tersebut. Maka perlu adanya fasilitas penunjang, salah satunya adalah jembatan. Jembatan merupakan konstruksi vital maka  harus didesain sedemikian rupa agar mampu menerima beban dengan baik. Jembatan tipe portal lengkung dapat menjadi alternatif untuk jembatan bentang panjang, karena selain bentuknya yang memiliki nilai estetika, jembatan dengan tipe pelengkung juga dapat mereduksi momen lentur sehingga penampang yang diperoleh menjadi lebih efisien. Abstract Kinovaro is a subdistrict where has many long and wide rivers and being obstacles in the process of fulfilling community needs and the development of the area. So that it needs to have a facilitis, one of that is a bridge. Bridges is important constructions so it needs to be designed carepully in order to have a proper calculation. Curved bridge type can be an alternative for long span bridges, because it has a nice aesthetic value, can also reduce bending moments so that it can provide an optimum cross section. The purpose of this Final Project is to obtain bending moments and curved axial forces, dimensions and reinforcement. The method used for structural analysis is the finite element method through the SAP2000 program, while for reinforcement design using the strength method based on SNI 2847-2013. The results of structural analysis, the are critical bending moment is 21869.332 kN.m and the critical axial force is 15944.307 kN, both of which are in the arching position. From the design results is found out that the girder dimensions of 60 x 80 cm. Thickness of the top arch is 60 cm and nearby support is 140 cm. While the column thickness at the top of the arch is 40 cm and nearby support is 80 cm. From the results of reinforcement design, the girder reinforcement of 16D25 mm was obtained on the support, and of 10D25 mm was at the middle length of the beam. Reinforcement of columns was obtained of D25-100 mm nearby support area and D25-200 mm at the top area. Whereas for the arches obtained of D25-80 mm for the supporting area and D25-100 mm at the top of the arch area. Tujuan dari penulisan Tugas Akhir ini adalah untuk mendapatkan momen lentur dan gaya aksial pelengkung, dimensi dan tulangan struktur yang efisien. Metode yang digunakan untuk analisa struktur adalah metode elemen hingga menggunakan program SAP2000, sedangkan untuk perencanaan tulangan menggunakan metode kekuatan berdasarkan SNI 2847-2013. Dari hasil analisa struktur diperoleh momen lentur pelengkung terbesar adalah 21869,332 kN.m dan gaya aksial terbesar adalah 15944,307 kN, keduanya berada pada perletakan pelengkung. Dari hasil perencanaan diperoleh dimensi gelagar 60 x 80 cm, tebal pada puncak pelengkung adalah 60 cm dan pada perletakan adalah 140 cm, sedangkan untuk tebal kolom pada puncak pelengkung adalah 40 cm dan pada perletakan adalah 80 cm. Dari hasil perencanaan tulangan diperoleh tulangan gelagar pada tumpuan 17D25 mm dan lapangan 10D25 mm. Tulangan kolom diperoleh tulangan D25-100 mm untuk daerah perletakan pelengkung dan D25-200 mm pada daerah puncak. Sedangkan untuk pelengkung diperoleh D25-80 mm untuk daerah perletakan dan D25-100 mm pada daerah puncak pelengkung.

Sign in / Sign up

Export Citation Format

Share Document