Modeling and analysis of knee joint impact damage in triple jump manipulators based on finite element method

2019 ◽  
Vol 10 (05) ◽  
pp. 1950030
Author(s):  
Mingquan Long
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Impact Damage ◽  
Jump Process ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Joint Injury ◽  
Jump Training ◽  
Knee Joint Injury ◽  
The Impact

In order to study the three jump training and competition on knee joint impact damage degree, left knee joint of one healthy male athletes is used as the research object, a complete knee three-dimensional model was established based on the jumper’s knee CT scan and magnetic resonance imaging (MRI), including the femur, tibia, fibula, patella and knee major cartilage, ligaments. The multi-body dynamics analysis (MDA) and finite element analysis (FEA) method are used to calculate the three jump, jump starting, landing process of athletes knee joint impact, the state should change the status of stress, strain and displacement. The results show that in the three jump process, the load on the lateral contact area of the knee joint is the largest, the displacement is the largest, and it increases with the impact of jump and landing. This exacerbated the degree of wear and tear of the tibia, it tends to induce knee injury in athletes. The results show that the combination of finite element and MDA can better study the knee joint’s shock and vibration during the three-level jump training and competition, and these open up a new research method for the knee joint injury. It also provides a certain reference for the prevention and treatment of knee joint injury.

Finite-element analysis of multi-body contacts for pile driving using a hydraulic pile hammer

2011 ◽  
Vol 225 (5) ◽  
pp. 1153-1161 ◽  
Author(s):  
Y Guo ◽  
J P Hu ◽  
L Y Zhang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Test Point ◽  
Pile Driving ◽  
Penalty Function Method ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Material Choice ◽  
Multi Body ◽  
The Impact

This article treats the pile driving as multi-body dynamic contacts. By using the penalty function method and three-dimensional model of finite-element method, the dynamic process of pile driving is acquired and a method for choosing the cushion material of the hydraulic pile hammer to improve driving efficiency is proposed. The process of pile driving in the real situation of an industrial experiment is simulated. The results of stress on test point are consistent with the test point. By analysing the stress distributed along the direction of pile radius and pile axis, the rule of the stress distribution on the pile is concluded. The rule for cushion material choice is obtained by comparing the influence for the impact stress with different elastic modulus ratio of the hammer cushion to the pile and the pile cushion to the pile.

Ballistic penetration damages and energy absorptions of stacked cross-plied composite fabrics and laminated panels

2020 ◽  
Vol 29 (9) ◽  
pp. 1465-1484
Author(s):  
Qingsong Wei ◽  
Bohong Gu ◽  
Baozhong Sun
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Impact Damage ◽  
Ballistic Impact ◽  
Body Armor ◽  
Element Analysis ◽  
Laminated Panels ◽  
Composite Fabrics ◽  
The Impact ◽  
Ballistic Penetration

Flexible fabrics have been widely used in body armor designs. Here we report ballistic impact damage of stacked cross-plied composite fabric and cross-plied laminated panels. The ballistic impact behaviors of stacked cross-plied composite fabric and cross-plied laminated panel have been tested with fragment-simulating projectiles under the strike velocity 550–600 m/s to explore the influence of the layers combination of fabric target on ballistic impact. Two types of macroscopic anisotropy continua finite element models based on fabric targets structures are established to analyze the ballistic mechanism of stacked cross-plied composite fabric and cross-plied laminated panels. The impact damage morphologies and energy absorptions have also been compared between the tests and finite element analysis results. We have found the stacked fabric construction absorbed more energy than their counterpart cross-plied laminated panel, while the laminated panel shows better structural integrity and stability during ballistic penetration.

scholarly journals Modeling and Validation of Heliostat Deformation due to Static Loading

2011 ◽  
Author(s):  
Adam C. Moya ◽  
Clifford K. Ho
Keyword(s):  
Finite Element ◽  
Structural Stability ◽  
Three Dimensional ◽  
Test Facility ◽  
Optical Performance ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Data Set ◽  
Static Test ◽  
The Impact

Accurate and reliable models are necessary to predict the performance and efficiencies of concentrating solar power plant components and systems such as heliostats and central receiver systems. Heliostat performance is impacted from effects such as wind and gravity, and understanding the impact of these loads on the optical performance can yield heliostat designs that are potentially cheaper, while maintaining required structural stability. Finite element models of heliostats at the National Solar Thermal Test Facility (NSTTF) at Sandia National Laboratories in Albuquerque, NM, were developed to simulate displacements under different loading scenarios. Solidworks was used to develop the three-dimensional model of the NSTTF heliostat, and Solidworks Simulation was used to perform the finite element analysis with simulated loads along different points of the heliostat. Static displacement tests were performed on the NSTTF heliostat in order to validate these FEA models. The static test results provide us with a data set in which to properly calibrate the FEA model to better represent the NSTTF heliostat for future simulations of optical performance with impacts of wind and gravity sag. In addition to a single model validation, this real world test provides a method to validate and understand the structural stability of a heliostat under static loads.

scholarly journals Finite element analysis for airfield asphalt pavements rutting prediction

2015 ◽  
Vol 63 (2) ◽  
pp. 397-403 ◽  
Author(s):  
G. Leonardi
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Permanent Deformation ◽  
Three Dimensional ◽  
Flexible Pavement ◽  
Asphalt Pavements ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
The Impact

Abstract This paper presents a numerical study of an aircraft wheel impacting on a flexible pavement. The proposed three dimensional model simulates the behaviour of flexible runway pavement during the landing phase. This model was implemented in a finite element code in order to investigate the impact of repeated cycles of loads on pavement permanent deformation. In the model a traditional multi-layer pavement structure was considered. In addition, the asphalt layer (HMA) was assumed to follow an elasto-viscoplastic behaviour. The results demonstrate the capability of the model in predicting the permanent deformation distribution in the asphalt layer

scholarly journals Biomechanical Responses and Injury Characteristics of Knee Joints under Longitudinal Impacts of Different Velocities

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Yan Xiong ◽  
Xueliang Zhao ◽  
Hongyi Xiang ◽  
Yunjiao Wang ◽  
Zhikang Liao ◽  
...  
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Knee Joints ◽  
Longitudinal Impact ◽  
Element Analysis ◽  
Human Knee ◽  
Bone Stress ◽  
Element Simulation ◽  
The Impact ◽  
Impact Experiments

Background and Objective. Knee joint collision injuries occur frequently in military and civilian scenarios, but there are few studies assessing longitudinal impacts on knee joints. In this study, the mechanical responses and damage characteristics of knee longitudinal collisions were investigated by finite element analysis and human knee impact tests. Materials and methods. Based on a biocollision test plateau, longitudinal impact experiments were performed on 4 human knee joints (2 in the left knee and 2 in the right knee) to measure the impact force and stress response of the bone. And then a finite element model of knee joint was established from the Chinese Visible Human (CVH), with which longitudinal impacts to the knee joint were simulated, in which the stress response was determined. The injury response of the knee joint-sustained longitudinal impacts was analyzed from both the experimental model and finite element analysis. Results. The impact experiments and finite element simulation found that low-speed impact mainly led to medial injuries and high-speed impact led to both medial and lateral injuries. In the knee joint impact experiment, the peak flexion angles were 13.8° ± 1.2, 30.2° ± 5.1, and 92.9° ± 5.45 and the angular velocities were 344.2 ± 30.8 rad/s, 1510.8 ± 252.5 rad/s, and 9290 ± 545 rad/s at impact velocities 2.5 km/h, 5 km/h, and 8 km/h, respectively. When the impact velocity was 8 km/h, 1 knee had a femoral condylar fracture and 3 knees had medial tibial plateau fractures or collapse fractures. The finite element simulation of knee joints found that medial cortical bone stress appeared earlier than the lateral peak and that the medial bone stress concentration was more obvious when the knee was longitudinally impacted. Conclusion. Both the experiment and FE model confirmed that the biomechanical characteristics of the injured femur and medial tibia are likely to be damaged in a longitudinal impact, which is of great significance for the prevention and treatment of longitudinal impact injuries of the knee joint.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

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