Development of a micromechanical finite element model from computed tomography images for shear modulus simulation of asphalt mixtures

2012 ◽  
Vol 30 ◽  
pp. 783-793 ◽  
Author(s):  
Erdem Coleri ◽  
John T. Harvey ◽  
Kai Yang ◽  
John M. Boone
2013 ◽  
Vol 2013 (0) ◽  
pp. _OS0510-1_-_OS0510-2_
Author(s):  
Mai NONOGAWA ◽  
Yuya KOZUKA ◽  
Tsuyoshi NISHIWAKI ◽  
Yasumasa NAKANISHI ◽  
Takaya KOBAYASHI

2016 ◽  
Vol 41 (2) ◽  
pp. 157-163
Author(s):  
Sathish Paul ◽  
Rekha Vijayakumar ◽  
Lazar Mathew ◽  
Sudesh Sivarasu

Background: The subtalar joint position during static stance is a crucial determinant of the peak plantar pressures and forms ideal reference point for any intervention in foot-related problems for leprosy-affected patients. Objectives: The study pursued the hypothesis through a three-dimensional model that stress will be minimal in the distal joints of the foot when the subtalar joint is in neutral static stance position. Study design: Finite element model. Methods: The computed tomography images of the feet for five patients suffering from Hansen’s disease having no muscle weakness and joint restriction were acquired. The gray intensities corresponding to the bones of the foot from the computed tomography images were three-dimensionally reconstructed. The three-dimensional model of the human foot, incorporating the realistic geometry, and the material properties of the hard tissues were then analyzed using a finite element solver for the stress distribution on bones of the foot. Results: The results demonstrate that the position of the calcaneum in the static stance position does contribute to the varying stress in the foot. Conclusion: The stresses in the bones of the foot are minimal while the subtalar is in neutral position; this position will be suitable for foot orthotic fabrication. Clinical relevance The clinicians, therapists, and podiatrists having less engineering skills can quickly assess the patient and get optimal results on the stress associated with the joints of the foot.


2011 ◽  
Vol 418-420 ◽  
pp. 50-54
Author(s):  
Shi Hong Pang ◽  
Juan Rong Ma ◽  
Zhen Zhu Ma ◽  
Li Chuang Wang

The shear modulus of PVB and SGP interlayer is analyzed. With the same conditions of load duration and temperature, the shear modulus of SGP interlayer is about fifteen times than that of PVB interlayer. A finite element model of laminated glass is established in this paper. The simulation results show that the maximum principal stress contours of PVB laminated glass change from a circular to a petal-shaped one and those of SGP laminated glass change form a quadrangular to a square-shaped one when the temperature rises from 20 degrees Celsius to 50 degrees Celsius.


2020 ◽  
Vol 70 (12) ◽  
pp. 4470-4476

In recent years the composites materials gained a major importance in all fields of engineering, because they offer a successful replacement for classical materials conferring similar elastic-mechanical properties to metal or non-metal alloys presenting several advantages such as reduced mass, chemical resistance etc. Considering this, during the design, dull knowledge of the elastic-mechanical characteristics is of high importance. The present paper aims to create a finite element model able to predict the shear elastic modulus of a double-layered composite material based on the elastic characteristics of its constituents. For this, once the elastic characteristics of the constituents determined, they could be used in the finite element analysis obtaining consequently the shear modulus for the composite material. Also, the shear elastic modulus of the resultant composite was determined experimentally. The results of the finite element model were compared to the experimental values in order to validate the finite element analyses results. Keywords: composites, fiberglass, shear modulus, FEM


Author(s):  
Suleyman Nazif Orhan ◽  
Mehmet Hamit Ozyazicioglu

The main purpose of this study is to develop a validated three-dimensional finite element model of sternum closure techniques. For this aim, the finite element method analysis results of three closure methods were compared with experimental test results. Also, three more closure techniques are simulated numerically to study the effect of the number of wires used in the manubrium and xiphoid regions. A three-dimensional model of polyurethane sternum foam was created based on computed tomography images. Six different closure techniques using steel wire, steel bands and ZipFix bands were modeled on the sternum and transferred into a three-dimensional finite element model. The sternum was modeled as an isotropic bilinear-elasto-plastic material, and nonlinear contact conditions were applied. The models were analyzed under lateral distraction loading, and load-displacement curves were obtained from displacements at the incision line. Allowable loads and stiffness values of the methods were evaluated from these curves. The results showed the importance of the including material as well as geometric nonlinearities in the simulations to obtain realistic results from the numerical analyses. Also, the analyses showed that closures that include steel or ZipFix bands are superior to conventional wiring, and addition of a single wire at the manubrium and xiphoid regions significantly improved the efficiency of the closure techniques.


Sign in / Sign up

Export Citation Format

Share Document