scholarly journals THE EFFECTS OF INTERBRACKET DISTANCE AND GABLE BENDS ON THE FORCE AND MOMENTS IN A SEGMENTED ARCH APPROACH: A NUMERICAL-EXPERIMENTAL STUDY

2018 ◽  
Vol 48 (1) ◽  
pp. 63-67
Author(s):  
M. A. FERREIRA ◽  
F. R.M. RODRIGUES ◽  
P. C. BORGES ◽  
M. A. LUERSEN

The present paper verified the effect of the interbracket distance on the force system developed by orthodontic retraction springs with two delta geometries measured during space closure when spaces between teeth are present. By using a platform transducer, five different interbracket distances were tested. Also the finite element method was applied to know the von Mises stress during spring activation/deactivation process. It was concluded that the interbracket distance and spring geometry variables have not caused significant influence on the force system resulting from activations, but activation has produced a statistical difference.

2010 ◽  
Vol 42 ◽  
pp. 48-53
Author(s):  
Jiu Yang Yu ◽  
Jiu Yang Gao ◽  
Wei Lin ◽  
Cheng Gang Wang ◽  
Yan Yang Wu ◽  
...  

The performance of reciprocating seals in rapping device of gasifier was studied through finite element method. The contact stress, Von-Mises stress, and friction power loss of O-ring and Sliding-ring combined Seal-ring were obtained. Meanwhile, the experimental study in performance of seal structures of rapping device were carried out. The results show that both of the seal structures are satisfied seal requirement, but compared with the Sliding-ring combined Seal-ring, the O-ring is easier to be destroyed and power loss of O-ring is higher than Sliding-ring combined Seal-ring. The results also verify the superiority of Sliding-ring combined Seal-ring in rapping device of gasifier.


2019 ◽  
Vol 2 (01) ◽  
pp. 23-26
Author(s):  
Lasinta Ari Nendra Wibawa

This study examines the design and stress analysis of a 10 ton capacity rocket lifting device using the finite element method. The material used is Aluminum alloy 7075. Finite element analysis is done numerically by using Autodesk Inventor Professional 2017. software The simulation results show that the structure of the rocket lift has Von Mises stress, deformation, mass, and safety factors of 46.34 MPa, 0.7947 mm, 186.75 kg, and 3.13.


2021 ◽  
Vol 68 (3) ◽  
pp. 374-378
Author(s):  
Roman Popescu ◽  
◽  
Stefan Cristea ◽  
Adrian Marius Pascu ◽  
Valentin Oleksik ◽  
...  

Background. This study aims to analyze the tibial component using the finite element method by cutting the tibial in frontal and sagittal planes at an angle between 1.5° (valgus and anterior tilt) and -1.5° (varus and posterior tilt). Methods. This experimental study used the finite element method as an useful tool for simulating the positioning of the tibial component in order to create a personal pre-operative planning. For the finite element method analysis, a geometrical model of a tibia from a cadaver was three – dimensionally scanned and the tibial component, polyethylene and cement, were three-dimensionally shaped in Computer-Aided Design program using material data such as Young modulus (gigapascal – GPa) and the Poisson coefficient. The analysis determined the equivalent von Mises stress, the maximum displacement of the components and the equivalent von Mises deformation. The results showed that equivalent tension and deformation have higher values in the tibia and the polyethylene, which deform faster than cement and the tibial component. In our study, we chose to simulate the tibial resection at a cutting angle ± 1.5° from neutral positioning (which is represented in frontal plane by the perpendicular on the mechanical axis and in sagittal plane by the posterior slope of 7 degree) in frontal and sagittal plane in order to find the minimum threshold from which the tibial component malalignment may begin to determine unfavorable effects. Results. Our results have shown detrimental effects begin to appear for the polyethene component at -1.5° in frontal plane, and the rest of the components at 1.5° in sagittal plane. Conclusion. This finding leads us to propose preoperative planning based on personal calculus of predefined angles, which may show the surgeon the optimal implantation position of the tibial component.


2014 ◽  
Vol 4 (3) ◽  
pp. 625-630
Author(s):  
A. Benouis ◽  
B. Serier ◽  
B. Bachir Bouiadjra

In this work we analyze three-dimensionally using the finite element method, the level and the Von Mises stress equivalent distribution induced around a cavity and between two cavities located in the proximal and distal bone cement polymethylmethacrylate (PMMA). The effects of the position around two main axes (vertical and horizontal) of the cavity with respect to these axes, of the cavity - cavity interdistance and of the type of loading (static) on the mechanical behavior of cement orthopedic are highlighted. We show that the breaking strain of the cement is largely taken when the cement in its proximal-lateral part contains cavities very close adjacent to each other. This work highlights not only the effect of the density of cavities, in our case simulated by cavity-cavity interdistance, but also the nature of the activity of the patient (patient standing corresponding to static efforts) on the mechanical behavior of cement.


2011 ◽  
Vol 402 ◽  
pp. 572-575
Author(s):  
Jun Li ◽  
Zhong Xian Wang ◽  
Feng Li ◽  
Chu Sheng Liu

This paper presents a novel structure of the dry coal separator with vibration fluidized bed and analyzed the dynamic characteristics of the vibration parts. The natural frequency, natural mode of vibration and dynamic response are calculated based on the finite element method. The results show that the natural frequency is far from working frequency, so that the structure can avoid resonance frequency effectively. The maximum von Mises stress is 0.01MPa which are allowed in the working condition.


2018 ◽  
Vol 195 ◽  
pp. 02007
Author(s):  
Taufiq Ilham Maulana ◽  
Hakas Prayuda ◽  
Bagus Soebandono ◽  
Martyana Dwi Cahyati ◽  
Eva Hanifatu Zahra

Castellated steel beams are made from normal steel beams cut into half with certain pattern and re-jointed to increase its height. This action results in many shapes of openings in its web, one of them being circular. Circular openings of castellated beams can also be implemented with single fix supported structures, but if uniform shape is used, it will reduce its effectiveness. In this paper, adoption of tapered shape on castellated beams with circular openings as cantilever structures will be discussed. This study uses 150x75x5x7 and 200x100x5.5x8 IWF sections with variations of opening diameters, opening spaces, and span lengths. The steel has a yield strength of 400 MPa and the analysis runs with solid element 10-node tetrahedron using the finite element method, by observing Von Mises stress and displacement. Free-licenced software such as LISAFEA 8.0 and FreeCAD are utilized for analysing and drawing solid elements. The result shows that the optimum height of IWF section for 150x75x5x7 is 230 mm and for 200x100x5.5x8 is 318 mm between span lengths of 2 m to 3.5 m. It can be concluded that each of the span lengths has various optimum diameters and opening spaces to acquire the smallest stress and displacement.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2934
Author(s):  
Naohiko Tamaya ◽  
Jun Kawamura ◽  
Yoshinobu Yanagi

The aim of this study was to evaluate the tooth movement efficacy of retraction springs made of a new β-titanium alloy, “gum metal”, which has a low Young’s modulus and nonlinear super elasticity. Using double loop springs incorporated into an archwire made of gum metal (GUM) and titanium molybdenum alloy (TMA), the maxillary anterior teeth were moved distally to close an extraction space. The long-term movements were simulated by the finite element method. Its procedure was constructed of two steps, with the first step being the calculation of the initial tooth movement produced by elastic deformation of the periodontal ligament, and in the second step, the alveolar socket was moved by the initial tooth movement. By repeating these steps, the tooth moved by accumulating the initial tooth movement. The number of repeating calculations was equivalent to an elapsed time. In the GUM and TMA springs, the anterior teeth firstly tipped lingually, and then became upright. As a result of these movements, the canine could move bodily. The amount of space closure in GUM spring was 1.5 times that in TMA spring. The initial tipping angle of the canine in the GUM spring was larger than that in the TMA spring. The number of repeating calculations required for the bodily movement in the GUM spring was about two times that in the TMA spring. It was predicted that the speed of space closure in the GUM spring was smaller than that in the TMA spring.


Author(s):  
T. S. Sultanmagomedov ◽  
◽  
R. N. Bakhtizin ◽  
S. M. Sultanmagomedov ◽  
T. M. Halikov ◽  
...  

Study is due to the possibility of loss of stability of the pipeline in the process of pumping a product with a positive operating temperature and the formation of thawing halos. The article presents the ways of solving the thermomechanical problem of pipeline displacement due to thawing. The rate of formation of a thawing halo is investigated depending on the initial temperatures of the soil and the pumped product. The developed monitoring system makes it possible to study the rate of occurrence of thawing halos in the process of pumping the product. An experimental study on the formation of thawing halos around the pipeline was carried out on an experimental model. A thermophysical comparative calculation of temperatures around the pipeline on a model by the finite element method has been carried out. Keywords: underground pipeline; permafrost; thawing halo; monitoring; operating conditions; stress–strain state.


Author(s):  
Lasinta Ari Nendra Wibawa

Crane is one of the heavy equipment that is widely used in the industry. The crane functions as a tool for lifting heavy loads and moving them from one place to another vertically and horizontally. In the LAPAN Garut office, it is used for the rocket assembly process. The study investigates the design and analysis of von Mises stress of crane structure with a capacity of 10 tons using mild steel material. The investigation was carried out numerically using Autodesk Inventor Professional 2017. The simulation results showed the Crane structure had a von Mises stress, deformation, mass, and safety factor respectively 63.73 MPa; 2,173 mm; 1.508,53 kg; and 3.25.Keywords: autodesk inventor 2017; finite element method; mild steel; stress analysis; von Mises stressABSTRAKCrane merupakan salah satu alat berat yang banyak digunakan dalam suatu industri. Crane berfungsi sebagai alat untuk mengangkat beban berat dan memindahkannya dari satu tempat ke tempat lain secara vertikal maupun horisontal. Di LAPAN Garut, Crane digunakan untuk proses perakitan roket. Penelitian ini meneliti tentang perancangan dan analisis tegangan von Mises struktur Crane dengan kapasitas 10 Ton menggunakan material mild steel. Analisis dilakukan secara numerik dengan menggunakan perangkat lunak Autodesk Inventor Professional 2017. Hasil simulasi menunjukkan struktur Crane memiliki tegangan von Mises, deformasi, massa, dan factor keamanan berturut-turut sebesar 63,73 MPa; 2,173 mm; 1.508,53 kg; dan 3,25.


2019 ◽  
Vol 1 (1) ◽  
pp. 13-20
Author(s):  
Brizeida Nohemí Ojeda

A study of stresses, displacements, and strain, based on a classic solid mechanic’s model, specifically a plate with hole, around which a stresses concentration, is presented. For this purpose, the stresses analysis was carried out in a hole concentrator subjected to traction. The model's material was ASTM A36. The stresses were analytically calculated, through von Mises' theory. In addition, the analysis of the stresses using the finite element method (FEM) was carried out. Subsequently, displacements and unitary deformation were determined in the part. The results obtained report an error of 8.7% between the stresses of von Mises through analytical calculus and using the FEM.


Sign in / Sign up

Export Citation Format

Share Document