scholarly journals Biomechanical evaluation and finite element analysis of axial-loading simulated experiment of wrist fracture

2020 ◽  
Author(s):  
Yuan-Wei Zhang ◽  
Liang-Yu Xiong ◽  
Zu-Tai Huang ◽  
Xin Xiao ◽  
Su-Li Zhang ◽  
...  

Abstract Objectives This study combined mechanical experiments and finite element analysis (FEA), and verified each other, to assess the biomechanical analysis and effect of wrist fracture, providing theoretical basis for the simulation experiments of wrist fracture and optimal design of wrist protector. Methods and Materials Six cadaveric wrists were included to create experimental specimens. After grouping, the wrist models were axially loaded under physiological load of 600 N, the stress magnitude and distribution of experimental group and control group were obtained. Moreover, a three-dimensional (3D) wrist finite element model (FEM) of a healthy volunteer was developed to verify the rationality and effectiveness of wrist models. Results Within the range of physiological load, the stress of radioulnar palmar unit was high and in shape of pressure, while the stress of radioulnar dorsal unit was relatively lower and in shape of tension. The stresses of radial distal palmar, ulnar distal palmar, radial distal dorsal, ulnar distal dorsal, radial proximal palmar and ulnar proximal palmar units in experimental group were less than those in control group. However, the stresses of radial proximal dorsal and ulnar proximal dorsal units were higher than those in control group. Conclusions Under physiological load, wearing wrist protector can apparently reduce the stress on radioulnar distal palmar, radioulnar proximal palmar and radioulnar distal dorsal units, while has no obvious effect on radioulnar proximal dorsal units. During the process of designing and improving the wrist protector, it is reasonable to place the stress center on radioulnar distal palmar and dorsal units.

2020 ◽  
Vol 48 (10) ◽  
pp. 030006052096688
Author(s):  
You-Liang Fan ◽  
Hai-Yun Xu ◽  
Ming-Yang Xia ◽  
Wen Zhang ◽  
Hui-Long Wen ◽  
...  

Objective To assess the biomechanical properties that influence wrist fracture, so as to provide the theoretical basis for simulation experiments to aid the optimal design of wrist protectors. Methods Six cadaveric wrists were included as experimental specimens. Wrist specimens wearing wrist protectors formed the experimental group and unprotected wrist specimens formed the control group. The wrist specimens were axially loaded under physiological loads and the stress magnitude and distribution of the experimental and control groups were obtained. A three-dimensional wrist finite element model of a healthy volunteer was developed to verify the rationality and effectiveness of the cadaveric wrist models. Results Under normal physiological loads, the stress on the radioulnar palmar unit was high and manifested in the form of pressure, while the stress on the radioulnar dorsal unit was lower and manifested in the form of tension. The stresses on the radial distal palmar, ulnar distal palmar, radial distal dorsal, ulnar distal dorsal, radial proximal palmar and ulnar proximal palmar units in the experimental group were less than those in the control group. Conclusion Under physiological loads, wearing a wrist protector can reduce the stress on the radioulnar distal palmar, radioulnar proximal palmar and radioulnar distal dorsal units, while having no obvious effect on the radioulnar proximal dorsal units.


2020 ◽  
Author(s):  
Jian Ying He ◽  
Li Zhang

Abstract Objective To evaluate the biomechanical analysis and effect of the wrist protector and provide a theoretical basis for wrist fractures and the optimal design of wrist protectors. Methods 6 cadaveric wrist models were axially loaded 600 N stress, and the stress magnitude and distribution of the experimental group (wearing wrist protectors) and control group were obtained. Furthermore, a three-dimensional finite element analysis was conducted to verify the scientificity and effectiveness of the models. Results The stresses on the radial distal palmar, ulnar distal palmar, radial distal dorsal, ulnar distal dorsal, radial proximal palmar and ulnar proximal palmar units in the experimental group were lower than those in the control group (P < 0.05). However, the stresses on the radial proximal dorsal and ulnar proximal dorsal units were higher than those in the control group (P>0.05). Conclusion The stress on the radioulnar palmar unit was high, while the radioulnar dorsal unit one was relatively low. Within the range of physiological loads, wearing wrist protectors can significantly reduce the stress on the radioulnar distal palmar, radioulnar proximal palmar and radioulnar distal dorsal units.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Shengnan Cao ◽  
Yuanzhen Chen ◽  
Feng Zhang ◽  
Shifei Sun ◽  
Congan Wang ◽  
...  

Cervical spondylotic radiculopathy (CSR) is the most commonly encountered cervical spine disorder. Cervical manipulation has been demonstrated as an effective therapy for patients. However, the mechanisms of manipulations have not been elucidated. A total of 120 cervical spondylotic radiculopathy patients were divided into the “three-dimensional balanced manipulation” treatment group (TBM group) and control group randomly. The control group was treated with traditional massage; the TBM treatment group was treated with “three-dimensional balanced manipulation” based on traditional massage. The symptoms and clinical efficacy of the patients were compared before and after treatment for one month. A three-dimensional finite element model was established. The mechanical parameters were imported to simulate TBM, and finite element analysis was performed. The results showed that the total effective rate was significantly higher in the TBM group compared with the control group. The biomechanical analysis showed the vertebral body stress was mainly distributed in the C3/4 spinous processes; the deformation mainly concentrated in the anterior processes of the C3 vertebral body. The intervertebral disc stress in the C3~C7 segment was mainly distributed in the anterior part of the C3/4 intervertebral disc, and the deformation extends to the posterior part of the C3/4 nucleus pulposus. In summary, these data are suggesting that TBM was effective in CSR treatment. The results of the finite element model and biomechanical analysis provide an important foundation for effectively avoiding iatrogenic injuries and improving the effect of TBM in the treatment of CSR patients.


2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1152
Author(s):  
Rafał Nowak ◽  
Anna Olejnik ◽  
Hanna Gerber ◽  
Roman Frątczak ◽  
Ewa Zawiślak

The aim of this study was to compare the reduced stresses according to Huber’s hypothesis and the displacement pattern in the region of the facial skeleton using a tooth- or bone-borne appliance in surgically assisted rapid maxillary expansion (SARME). In the current literature, the lack of updated reports about biomechanical effects in bone-borne appliances used in SARME is noticeable. Finite element analysis (FEA) was used for this study. Six facial skeleton models were created, five with various variants of osteotomy and one without osteotomy. Two different appliances for maxillary expansion were used for each model. The three-dimensional (3D) model of the facial skeleton was created on the basis of spiral computed tomography (CT) scans of a 32-year-old patient with maxillary constriction. The finite element model was built using ANSYS 15.0 software, in which the computations were carried out. Stress distributions and displacement values along the 3D axes were found for each osteotomy variant with the expansion of the tooth- and the bone-borne devices at a level of 0.5 mm. The investigation showed that in the case of a full osteotomy of the maxilla, as described by Bell and Epker in 1976, the method of fixing the appliance for maxillary expansion had no impact on the distribution of the reduced stresses according to Huber’s hypothesis in the facial skeleton. In the case of the bone-borne appliance, the load on the teeth, which may lead to periodontal and orthodontic complications, was eliminated. In the case of a full osteotomy of the maxilla, displacements in the buccolingual direction for all the variables of the bone-borne appliance were slightly bigger than for the tooth-borne appliance.


2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.


Author(s):  
Luiz T. Souza ◽  
David W. Murray

The paper presents results for finite element analysis of full-sized girth-welded specimens of line pipe and compares these results with the behavior exhibited by test specimens subjected to constant axial force, internal pressure and monotonically increasing curvatures. Recommendations for the ‘best’ type of analytical finite element model are given. Comparisons between the behavior predicted analytically and the observed behavior of the experimental test specimens are made. The mechanism of wrinkling is explained and the evolution of the deformed configurations for different wrinkling modes is examined. It is concluded that the analytical tools now available are sufficiently reliable to predict the behavior of pipe in a manner that was not previously possible and that this should create a new era for the design and assessment of pipelines if the technology is properly exploited by industry.


2020 ◽  
Author(s):  
Yuan-Wei Zhang ◽  
Liang-Yu Xiong ◽  
Zu-Tai Huang ◽  
Xin Xiao ◽  
Su-Li Zhang ◽  
...  

Abstract The authors have withdrawn this preprint due to author disagreement.


Sign in / Sign up

Export Citation Format

Share Document