scholarly journals The Multi-Parametric Weight Optimization of a Hydraulic Actuator

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 60
Author(s):  
Luigi Solazzi ◽  
Andrea Buffoli ◽  
Raffaele Formicola

This research was derived from the experimental observation that hydraulic actuators are positioned on machines that are subjected to movements and whose dynamic actions, the accelerations, are very high; it is acceptable to think of an actuator for an anthropomorphic robot. From this point of view, the weight of the actuator plays a fundamental role in the performance of the machine. In order to face this problem, a real hydraulic cylinder has been designed (for use on an earth moving machine) both analytically (adopting the theories of continuous mechanics) and numerically through finite element analysis. The results obtained were then generalized by determining functions that in relation to specific values of the variables, such as working pressure, allow one to determine the minimum weight of the component and its geometric configuration. The functions also made it possible to identify the most significant contributions to the overall weight of the component and therefore the elements on which to focus the subsequent lightening process. In particular, the greatest contribution is made by obtaining relations that are completely general and therefore adaptable to different case studies.

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Hyeong-Yeon Lee ◽  
Kee-Nam Song ◽  
Yong-Wan Kim ◽  
Sung-Deok Hong ◽  
Hong-Yune Park

A process heat exchanger (PHE) transfers the heat generated from a nuclear reactor to a sulfur-iodine hydrogen production system in the Nuclear Hydrogen Development and Demonstration, and was subjected to very high temperature up to 950°C. An evaluation of creep-fatigue damage, for a prototype PHE, has been carried out from finite element analysis with the full three dimensional model of the PHE. The inlet temperature in the primary side of the PHE was 950°C with an internal pressure of 7 MPa, while the inlet temperature in the secondary side of the PHE is 500°C with internal pressure of 4 MPa. The candidate materials of the PHE were Alloy 617 and Hastelloy X. In this study, only the Alloy 617 was considered because the high temperature design code is available only for Alloy 617. Using the full 3D finite element analysis on the PHE model, creep-fatigue damage evaluation at very high temperature was carried out, according to the ASME Draft Code Case for Alloy 617, and technical issues in the Draft Code Case were raised.


2013 ◽  
Vol 740 ◽  
pp. 319-322 ◽  
Author(s):  
Young Choon Lee ◽  
Nam Jin Jeon ◽  
Cheol Kim ◽  
Seo Yeon Ahn ◽  
Myung Jae Cho

Finite element analysis was accomplished for a steering knuckle component of a small bus to see whether the static and fatigue strength requirements were satisfied or not. The knuckle was modeled with ANSYS 10-node quadratic elements. The cyclic fatigue load was applied and Soderberg criteria were applied to check the fatigue life. The knuckle structure has an infinite life (10-6 cycle) judging from the fatigue analyses. Shape optimization based on the gradient based method has been performed in order to find out the knuckle shape that has a minimum weight and satisfies the static and fatigue strength requirements. As a result of shape optimization, the weight of the steering knuckle was reduced 8%.


2018 ◽  
Vol 3 (1) ◽  
pp. 832
Author(s):  
Carolina Rivera Olarte ◽  
Juliana Velásquez Gómez ◽  
Yesid Montoya Góez

CrossFit® in people with a upper limb disability is a challenge in designing elements for weight lifting above the head due to: fixation, carrying capacity and safety. This paper presents a proposal for the design of a prosthesis prototype for CrossFit® weightlifting practice with wrist disarticulation, based on the product design methodology of Ulrich and Eppinger, including detailed design through Finite Element Analysis (FEA) and tensile failure test in a load system INSTRON® 5582. The results show from the mechanical point of view that the design allows the lifting of loads up to 2000N.Keywords: Prosthesis, upper limb disability, CrossFit®, weightlifting. 


2011 ◽  
Vol 12 (4) ◽  
pp. 259-264 ◽  
Author(s):  
Anirudh K Mathur ◽  
Vinaya S Pai ◽  
S Nandini ◽  
Anirban Sarmah

ABSTRACT Aim The purpose of this three-dimensional (3D) finite element study was to investigate orthodontic loading simulation on a single endosseous implant and its surrounding osseous structure, to analyze the resultant stresses and to identify the changes in the bone adjacent to the implant following orthodontic loading. Materials and methods Two models were constructed using finite element method consisting of endosseous dental implant and the surrounding bone. In the first model, the contact between the implant and the bone was simulated showing no osseointegration, while the second model showed 100% osseointegration. Simulated horizontal loads of 20 N, at 90° from the long axis, were applied to the top of the implant. The study simulated loads in a horizontal direction, similar to a distalmesial orthodontic movement. Results In the first model, the stress was mainly concentrated at the neck of the implant and at the closest surrounding bone. In the second model, the stress was chiefly concentrated at the neck of the implant at the level of the cortical superficial bone. The stresses decreased in the cancellous bone area. On the implant, the highest stress concentration was at the first cervical thread decreasing uniformly to the apex. The stress distribution on the mesial and distal sides showed that the maximum compressive stress was localized mesially and the maximum tensile stress distally. If both models are compared, it can be observed that the stresses were less and more evenly distributed in model 1 (initial stability) than in model 2 when osseointegration was assumed. Conclusion A lack of bony support for the implant represents an unfavorable situation from biomechanical point of view that should be considered and solved. As clinical problems mostly occur at the marginal bone region (bacterial plaque accumulation, overcontoured abutments, infections, osseous defects), attention should be focused on this region. Clinical significance When osseointegrated implants are primarily used as anchorage for orthodontic purposes and then as fixed prosthesis, the functional and structural union of titanium to bone should be preserved. How to cite this article Sarmah A, Mathur AK, Gupta V, Pai VS, Nandini S. Finite Element Analysis of Dental Implant as Orthodontic Anchorage. J Contemp Dent Pract 2011;12(4):259-264.


Author(s):  
Hyeong-Yeon Lee ◽  
Kee-Nam Song ◽  
Yong-Wan Kim ◽  
Sung-Deok Hong ◽  
Hong-Yune Park

A process heat exchanger (PHE) transfers the heat generated from a nuclear reactor to a sulfur-iodine hydrogen production system in the NHDD (Nuclear Hydrogen Development and Demonstration), and was subjected to very high temperature up to 950°C. An evaluation of creep-fatigue damage, for a prototype PHE, has been carried out from finite element analysis with the full three dimensional model of the PHE. The inlet temperature in the primary side of the PHE was 950°C with an internal pressure of 7MPa while the inlet temperature in the secondary side of the PHE is 500°C with internal pressure of 4MPa. The candidate materials of the PHE were Alloy 617 and Hastelloy X. In this study, only the Alloy 617 was considered because the high temperature design code is available only for Alloy 617. Using the full 3D finite element analysis on the PHE model, creep-fatigue damage evaluation at very high temperature was carried out, according to the ASME Draft Code Case for Alloy 617, and technical issues in the draft Code Case were raised.


2020 ◽  
Author(s):  
M. Pérez Bayas ◽  
S. Coba ◽  
E. Pozo ◽  
M. Ordoñez

El presente trabajo demuestra el proceso en la investigación inicial para el desarrollo de un actuador giratorio hidráulico para fines terapéuticos. El dispositivo se basa en la necesidad de un aparato motor aplicable a la rehabilitación de lesiones de rodilla, con la capacidad de ser usado en la hidroterapia, para lo cual se realiza una revisión bibliográfica y se define el comportamiento del actuador en función a los fenómenos de presión y flujo, definiendo así las funciones para el par y la velocidad del actuador. En una primera etapa, se presenta un modelo simplificado del actuador, para luego simular el comportamiento mecánico de los componentes con la ayuda de un software de análisis de elementos finitos. Concluyendo con la validación de los elementos principales del actuador, llamados eje y aleta, sometidos a los parámetros delimitados para la aplicación, dejando la base de un modelo del mecanismo útil para el cálculo de la dinámica del sistema como siguiente paso de la investigación. The present work demonstrates the process in the research and development of a hydraulic rotary actuator for therapeutic purposes. The device is based on the need for a motor apparatus applicable to the rehabilitation of knee injuries, with the ability to be used in hydrotherapy, for which a literature review is performed and the behavior of the actuator is defined depending on the pressure and flow phenomena, thus defining the functions for the torque and speed of the actuator. In the first stage, a simplified model of the actuator is presented, to proceed to simulate the mechanical behavior of the components with the help of finite element analysis software. Concluding with the validation of the main elements of the actuator, called axis and fin, subject to the parameters defined for the application, leaving the basis of a model of the mechanism useful for calculating the dynamics of the system as the next step of the investigation. Palabras claves: Actuador rotatorio, Simulación, Diseño, Mecánica hidráulica. Keywords: Rotary actuator, Simulation, Design, Hydraulic Mechanics.


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