scholarly journals Efficient Mounting of a Tank for the Transport of Flammable Liquids on a Freight Vehicle

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8385
Author(s):  
Dimitrios Koulocheris ◽  
Clio Vossou
Keyword(s):  
Dynamic Behavior ◽  
Structural Integrity ◽  
Load Sharing ◽  
Von Mises Stress ◽  
Efficient Design ◽  
Fe Method ◽  
Liquid Material ◽  
Von Mises ◽  
Supporting Structures

The design and construction of tanks used for the carriage of dangerous liquid materials fall within strict standards (i.e., EN13094:2015, R111). According to these standards, their supporting structures (Ss), used for the mounting of the tank on the freight vehicle, need to be able to sustain the developed stresses. Optimizing the number of supporting structures can lead to more efficient tank designs that allow the tank to transport more liquid material and need less time to be manufactured. In the present paper, the effect of the reduction of the number of supporting structures in (a) the structural integrity of the tank construction, (b) its dynamic behavior and (c) the load-sharing of the tank to the axles of the freight vehicle is investigated using the finite element (FE) method. As a case study a box-shaped tank mounted on a four-axle freight vehicle with a technical permissible maximum laden mass of 35 tn, five Ss are used. Four FE models with a decreasing number of Ss were built in ANSYS® 2020R1 CAE Software and their structural integrity was investigated. For each design, a feasible design was developed and evaluated in terms of structural integrity, dynamic behavior and axle load distribution. The results of the FE analysis were reviewed in terms of maximum equivalent Von Mises stress and stress developed on the welding areas. Additionally, the axle-load sharing was qualitatively assessed for all feasible designs. The main outcome of this work is that, overall, the use of two Ss leads to a more efficient design in terms of the manufacturing and the mounting of the tank construction on the vehicle and on a more efficient freight vehicle. More specifically, the reduction of the number of Ss from five to two lead to reduction of the tank tare weight by 9.6% with lower eigenfrequencies.

scholarly journals Mechanical Strength Study of a Cranial Implant Using Computational Tools

2022 ◽  
Vol 12 (2) ◽  
pp. 878
Author(s):  
Pedro O. Santos ◽  
Gustavo P. Carmo ◽  
Ricardo J. Alves de Sousa ◽  
Fábio A. O. Fernandes ◽  
Mariusz Ptak
Keyword(s):  
Structural Integrity ◽  
Mechanical Performance ◽  
Skull Fracture ◽  
Human Head ◽  
Element Model ◽  
Von Mises Stress ◽  
Cranial Implant ◽  
Von Mises ◽  
Two Parameters ◽  
The Brain

The human head is sometimes subjected to impact loads that lead to skull fracture or other injuries that require the removal of part of the skull, which is called craniectomy. Consequently, the removed portion is replaced using autologous bone or alloplastic material. The aim of this work is to develop a cranial implant to fulfil a defect created on the skull and then study its mechanical performance by integrating it on a human head finite element model. The material chosen for the implant was PEEK, a thermoplastic polymer that has been recently used in cranioplasty. A6 numerical model head coupled with an implant was subjected to analysis to evaluate two parameters: the number of fixation screws that enhance the performance and ensure the structural integrity of the implant, and the implant’s capacity to protect the brain compared to the integral skull. The main findings point to the fact that, among all tested configurations of screws, the model with eight screws presents better performance when considering the von Mises stress field and the displacement field on the interface between the implant and the skull. Additionally, under the specific analyzed conditions, it is observable that the model with the implant offers more efficient brain protection when compared with the model with the integral skull.

A New Anchorage Device for Orthodontic Applications

2013 ◽  
Author(s):  
Mohamad Najari ◽  
Marwan El-Rich ◽  
Samer Adeeb ◽  
Bachar Taha
Keyword(s):  
Cortical Bone ◽  
Shear Force ◽  
Vertical Shear ◽  
Von Mises Stress ◽  
Fe Method ◽  
Screw Head ◽  
Load Bearing ◽  
New Device ◽  
Von Mises ◽  
Orthodontic Forces

In orthodontic treatment, anchorage is the most important element that affects the treatment’s success. To improve the load bearing capacity of the anchorage there are several devices developed in recent decades such as midpalatal implants and onplants but they also have limitation on directions of applied load and their support position adjustability. The purpose of this study was to investigate the efficiency of a new anchorage device by analyzing the load-bearing and stress distribution among the cortical and cancellous bones of the mandible as well as the anchorage system components using nonlinear 3D Finite Element (FE) method. The new device is composed of an adjustable stainless steel plate equipped with bracket and mounted with two titanium mini-screws into the mandible. The response of this new system was compared to an isolated mini-screw system under different loading scenarios. A maximum of 500gr force was applied in different directions on the bracket and the isolated mini-screw head to simulate the orthodontic loading. Using the new anchorage device reduced von-Mises stress in the whole structure approximately by 50% comparing to the isolated mini-screw. In the cortical bone and depending on the direction of the applied force, von-Mises stress decreased from 6 to 3MPa under vertical shear force and from 6 to 1.5MPa under horizontal and inclined shear forces. In the cancellous bone the stress decreased similarly as in the cortical bone from 0.6 to ≈0.3MPa under horizontal and inclined shear. Under vertical shear force the decrease was less significant from 0.57MPa to 0.5MPa. This new device while offering wide fields of orthodontic forces applications thanks to its bracket provides the same resistive force (500gr) as the isolated mini-screw with much lower stresses in the bone and anchorage implant as well. The next step is to investigate the efficiency of this new device in the teeth movement.

Simulation of Brain Response to Noncontact Impacts Using Coupled Eulerian–Lagrangian Method

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Miao Na ◽  
Timothy J. Beavers ◽  
Abhijit Chandra ◽  
Sarah A. Bentil
Keyword(s):  
Brain Tissue ◽  
Mechanical Response ◽  
Brain Regions ◽  
Von Mises Stress ◽  
Fe Model ◽  
Brain Response ◽  
Fe Method ◽  
Angular Velocities ◽  
Von Mises ◽  
The Brain

Abstract Finite element (FE) method has been widely used for gaining insights into the mechanical response of brain tissue during impacts. In this study, a coupled Eulerian−Lagrangian (CEL) formulation is implemented in impact simulations of a head system to overcome the mesh distortion difficulties due to large deformation in the cerebrospinal fluid (CSF) region and provide a biofidelic model of the interaction between the brain and skull. The head system used in our FE model is constructed from the transverse section of the human brain, with CSF modeled by Eulerian elements. Spring connectors are applied to represent the pia-arachnoid connection between the brain and skull. Validations of the CEL formulation and the FE model are performed using the experimental results. The dynamic response of brain tissue under noncontact impacts and the brain regions susceptible to injury are evaluated based on the intracranial pressure (ICP), maximum principal strain (MPS), and von Mises stress. While tracking the critical MPS location on the brain, higher likelihood of contrecoup injury than coup injury is found when sudden brain−skull motion takes place. The accumulation effect of CSF in the ventricle system, under large relative brain−skull motion, is also identified. The FE results show that adding relative angular velocities, to the translational impact model, not only causes a diffuse high strain area, but also cause the temporal lobes to be susceptible to cerebral contusions since the protecting CSF is prone to be squeezed away at the temporal sites due to the head rotations.

scholarly journals Multiaxial fatigue criteria applied to motor crankshaft in thermoelectric power plants

2019 ◽  
Vol 300 ◽  
pp. 04003
Author(s):  
Marcos Venicius S. Pereira ◽  
Fathi Aref Darwish ◽  
André Feiferis ◽  
Tiago Lima Castro
Keyword(s):  
Thermoelectric Power ◽  
Power Plants ◽  
Structural Integrity ◽  
Fatigue Behavior ◽  
Multiaxial Fatigue ◽  
Stress Fields ◽  
Von Mises Stress ◽  
Thermoelectric Power Plants ◽  
Octahedral Shear Stress ◽  
Von Mises

Fatigue failures of motor crankshafts operating in thermoelectric power plants have recently been reported. Stress fields provided by finite element calculations at critical points of a crankshaft that failed in service are used to test the structural integrity of the component. Taking into account the fact that the stresses acting at a given point are most likely out of phase, multiaxial fatigue criteria based on the von Mises stress are considered to be most suitable for predicting the fatigue behavior of the crankshaft. Using the von Mises stress, it was also possible to apply octahedral shear stress-based criteria and the results obtained have indicated that the crankshaft made of DIN 34CrNiMo6 steel should not suffer fatigue failure under the action of the stress fields in question. However, such failures have been occurring and this apparent discrepancy is presented and briefly discussed in the present study.

A personalized mandibular implant with supporting and porous structures designed with topology optimization – a case study of canine

2019 ◽  
Vol 25 (2) ◽  
pp. 417-426 ◽  
Author(s):  
Kangjie Cheng ◽  
Yunfeng Liu ◽  
Chunyan Yao ◽  
Wenquan Zhao ◽  
Xu Xu
Keyword(s):  
Topology Optimization ◽  
Optimal Design ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Von Mises Stress ◽  
Content Type ◽  
Optimized Model ◽  
Supporting Structures ◽  
External Shape

Purpose The purpose of this study is to obtain a titanium mandibular implant that possesses a personalized external shape for appearance recovery, a supporting structure for physiological loading and numerous micro-pores for accelerating osseointegration. Design/methodology/approach A three-dimensional intact mandibular model of a beagle dog was created from cone-beam computerized tomography scans. A segment of the lower jaw bone was resected and replaced by a personalized implant with comprehensive structures including a customized external shape, supporting structures and micro-pores, which were designed by topology optimization. Then with FEM analysis, the stress, displacement distribution and compliance of the designed implant were compared with the non-optimized model. The weight of the optimized implant that was fabricated by SLM with titanium alloy powder was measured and contrasted with the predicted non-optimized model for evaluating the viability of the design. Findings The FEM results showed the peaks of von Mises stress and displacement on the optimized implant were much lower than those of the implant without optimization. With topology optimization, the compliance of the implant decreased significantly by 53.3 per cent, and a weight reduction of 37.2 per cent could be noticed. Originality/value A design strategy for personalized implant, with comprehensive structures and SLM as the fabrication method, has been developed and validated by taking a canine mandible as the case study. With comprehensive structures, the implant presented good biomechanical behaviors thanks to the most appropriate supporting structures obtained by optimal design. The topological optimal design combined with SLM printing proved to be an effective method for the design and fabrication of personalized implant with complex structures.

scholarly journals Structural analysis of deep soil loosening machine MAS-65

2019 ◽  
Vol 112 ◽  
pp. 03034 ◽  
Author(s):  
Mihai Gabriel Matache ◽  
Remus Marius Oprescu ◽  
Dragos Nicolae Dumitru ◽  
Gabriel Valentin Gheorghe ◽  
Dan Cujbescu ◽  
...  
Keyword(s):  
Structural Analysis ◽  
3D Model ◽  
Structural Integrity ◽  
Field Tests ◽  
Von Mises Stress ◽  
Strain Gages ◽  
Structural Failure ◽  
Deep Soil ◽  
Distribution Maps ◽  
Von Mises

Deep soil loosening machine MAS 65 is destined to work soil at depths exceeding 45 cm, thus the machine’s frame is subjected to loads which could affect its structural integrity. Within this paper a static structural analysis was performed on the machine’s 3D model using finite element method and strain and stress distribution maps were created. Using the Von Mises stress map there were identified several critical points which could fail during normal exploitation conditions and which should be monitored by strain gages during field tests in order to prevent structural failure.

An Analytical Study of the Structural Integrity of an LPG Storage Tank under Wind Load

2015 ◽  
Vol 741 ◽  
pp. 115-118 ◽  
Author(s):  
Bong Kwan Park ◽  
Jae Min Kim ◽  
Chang Min Keum ◽  
C. Kim ◽  
Heon Oh Choi
Keyword(s):  
Storage Tank ◽  
Structural Integrity ◽  
Element Model ◽  
Wind Load ◽  
Von Mises Stress ◽  
Shell Elements ◽  
Analytical Technique ◽  
Von Mises ◽  
Design Factors ◽  
Important Design

Since the wall thicknesses of most large LPG storage tanks are thin while their diameters are large, their structural integrity is one of the most important design factors. The tanks are mainly located near the waterfront for efficient transport and accessibility. This leads to exposure to wind loads, which should be considered in the design of the tanks. This paper describes an analytical technique for determining the structural integrity of a 45m diameter-LPG storage tank in the case of a wind load based on API 620 code. A finite element model for the tank was made using shell elements and analyzed under 50 m/s wind. The calculated maximum von-Mises stress was 103 MPa whereas the yield strength of tank’s material is 222 MPa. This result shows that the structural integrity of the tank is assured.

scholarly journals Streamlining Metal Poles

2000 ◽  
Vol 122 (04) ◽  
pp. 68-70
Author(s):  
Ioan Giosan ◽  
Ted Brockman
Keyword(s):  
Transmission Lines ◽  
Structural Integrity ◽  
Base Plate ◽  
Von Mises Stress ◽  
Roll Forming ◽  
Forming Process ◽  
Pole Type ◽  
Von Mises ◽  
The Impact ◽  
Stress Analyses

This article discusses that an engineering firm is using software to ensure the structural integrity of all types of pole designs. West Coast Engineering (WCE) Group in Delta, British Columbia, Canada, performed several linear stress analyses using software to optimize the insulator bracket, which supports the transmission lines on the tangent poles. Physical testing was used to verify the accuracy of the analysis results. WCE began the structural analyses by analyzing the shafts of each pole type under ultimate loading, which was determined by Ian Hayward International using standard industry calculations. WCE performed linear static stress analyses on the models and evaluated the von Mises stress criteria for ductile materials to assess the stress results. With the pole shaft and base plate structures verified, engineers focused the next analysis on the insulator brackets of the tangent structure to optimize the load bearing capability and material thickness. With the predictable loading capacity requirements confirmed for the designs, WCE expanded the study to include a simulation of the impact loading that can result from a head-on vehicle collision. WCE is continuing the use of Algor software in the design of poles and in the development of new pole manufacturing equipment. Currently, the company is using it to simulate and optimize a roll forming process.

scholarly journals Analysis of the Risk of Wear on Cemented and Uncemented Polyethylene Liners According to Different Variables in Hip Arthroplasty

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7243
Author(s):  
Basilio De la Torre ◽  
Loreto Barrios ◽  
Juan De la Torre-Mosquera ◽  
Julia Bujan ◽  
Miguel A. Ortega ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Von Mises Stress ◽  
Fe Method ◽  
Center Of Rotation ◽  
Total Hip ◽  
Significant Difference ◽  
Acetabular Fixation ◽  
Acetabular Side ◽  
Von Mises

Wear debris in total hip arthroplasty is one of the main causes of loosening and failure, and the optimal acetabular fixation for primary total hip arthroplasty is still controversial because there is no significant difference between cemented and uncemented types for long-term clinical and functional outcome. To assess and predict, from a theoretical viewpoint, the risk of wear with two types of polyethylene liners, cemented and uncemented, a simulation using the finite element (FE) method was carried out. The risk of wear was analyzed according to different variables: the polyethylene acetabular component’s position with respect to the center of rotation of the hip; the thickness of the polyethylene insert; the material of the femoral head; and the relationship of the cervical–diaphyseal morphology of the proximal end of the femur to the restoration of the femoral offset. In all 72 simulations studied, a difference was observed in favour of a cemented solution with respect to the risk of wear. With regard to the other variables, the acetabular fixation, the thickness of the polyethylene, and the acetabular component positioning were statistically significant. The highest values for the risk of wear corresponded to a smaller thickness (5.3 mm), and super-lateral positioning at 25 mm reached the highest value of the von Mises stress. According to our results, for the reconstruction of the acetabular side, a cemented insert with a thickness of at least 5 mm should be used at the center of rotation.

scholarly journals Fluid-Structure Interaction on The Design of Fully Assembled Shell Eco-Marathon (SEM) Prototype Car

CFD letters ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 115-136
Author(s):  
Hedy Soon Keey Tiew ◽  
Ming Wei Lee ◽  
Wei Shyang Chang ◽  
Mohammad Hafifi Hafiz Ishak ◽  
Farzad Ismail
Keyword(s):  
Structural Integrity ◽  
Fibre Composite ◽  
Fuel Efficiency ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Von Mises Stress ◽  
Fluid Structure ◽  
Structure Interaction ◽  
High Fuel Efficiency ◽  
Von Mises

To achieve high fuel efficiency, vehicles designs are inclined to choose lightweight materials and structures. However, these structures are generally weak, and structural integrity is a common concern. The purpose of this paper is to carry out fluid-structure interaction (FSI) study in one-way coupling analysis on a Shell Eco Marathon (SEM) prototype car which travels in a low-speed range to analyse its structural response. A new set of economical materials is proposed and analysed with the concern on self-fabrication process. The Flax fibre composite is introduced as a part of the proposed material set due to its environmental and economic advantages. The study herein is purely a numerical simulation work as a first approach to design a sustainable SEM prototype car. The fully assembled SEM prototype car was analysed with the proposed materials with ANSYS Workbench in the coupling of the fluid (ANSYS Fluent) and structural solver (ANSYS Mechanical) in a one-way FSI. Even with a thin shell design, the proposed material only experiences minimum deformations. The simulations also reveal that the maximum von-Mises stress experienced, after considered the safety factor, is still several order lower than the yield strength. This study has confirmed that the car design has fulfilled its structural requirements to operate at the design speed.

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