Rupture Simulation of Three Dimensional Elastoplastic Structures under Dynamic Loading

2009 ◽  
Author(s):  
G. Leclère ◽  
A. Nême ◽  
J.Y. Cognard
Keyword(s):  
Dynamic Loading ◽  
Three Dimensional

Dynamic Fracture Parameters and Calculations for 3-D Cracks

2003 ◽  
Author(s):  
Wing Cheng ◽  
Shigeru Itoh
Keyword(s):  
Dynamic Loading ◽  
Dynamic Fracture ◽  
Structural Integrity ◽  
Three Dimensional ◽  
Welding Process ◽  
Fracture Parameter ◽  
Integrity Assessment ◽  
Fracture Parameters ◽  
Cracked Structures ◽  
Geometrical Factors

Welded structures such as armor fighting vehicles, shipboard structures or munitions systems are required to sustain intense and rapidly applied dynamic loading due to gun firings, impact of enemy munitions and extreme loading from accident scenarios. Flaws are normally found in various extents in welds depending on quality control of the welding process. It is important to determine critical flaw sizes of three-dimensional cracks in a welded joint under dynamic loading introduced by the above scenarios. Calculation of dynamic fracture parameters of the three-dimensional cracks of various geometrical factors at different locations is important for use the crack growth evaluation, flacture and structural integrity assessment. This paper summarizes the methodologies and results of the dynamic fracture parameter calculations for stationary three-dimensional cracks in cracked structures subjected to both static and dynamic loads.

Three Dimensional Seismic Isolation System for Next-Generation Nuclear Power Plant With Rolling Seal Type Air Spring and Hydraulic Rocking Suppression System

2005 ◽  
Author(s):  
Takahiro Shimada ◽  
Junji Suhara ◽  
Kazuhiko Inoue
Keyword(s):  
Dynamic Loading ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Loading Test ◽  
Isolation System ◽  
Ability Test ◽  
Base Isolation System ◽  
Suppression System

Three dimensional (3D) seismic isolation devices have been developed to use for the base isolation system of the heavy building like a nuclear reactor building. The developed seismic isolation system is composed of rolling seal type air springs and the hydraulic type springs with rocking suppression system for vertical base isolation device. In horizontal direction, the same laminated rubber bearings are used as horizontal isolation device for these systems. The performances and the applicability have already been evaluated by the technical feasibility tests and performance tests for each system. In this study, it was evaluated that the performance of the 3D base isolation system with rolling seal type air springs combined with hydraulic rocking suppression devices. A 1/7 scaled model of the 3D base isolation devices were manufactured and some performance test were executed for each device. For the rolling seal type air springs, dynamic loading test was executed with a vibration table, and pressure resistant ability test was executed for reinforced air springs. In the dynamic loading test, it is confirmed that the natural period and damping performance were verified. In the pressure resistant ability test, it is confirmed that the air springs had sufficient strength. For the hydraulic rocking suppression system, forced dynamic loading test was carried out in order to measure the frictional and oil flow resistance force on each cylinder. And the vibration table tests were carried out with supported weight of 228 MN in order to evaluate and to confirm the horizontal and vertical isolation performance, rocking suppression performance, and the applicability of the this seismic isolation system as the combined system. 4 rolling seal type air springs and 4 hydraulic load-carrying cylinders with rocking suppression devices supported the weight. As a result, the proposed system was verified that it could be applied to the actual nuclear power plant building to be target.

scholarly journals Dynamic loading of human engineered heart tissue enhances contractile function and drives a desmosome-linked disease phenotype

2021 ◽  
Vol 13 (603) ◽  
pp. eabd1817
Author(s):  
Jacqueline M. Bliley ◽  
Mathilde C. S. C. Vermeer ◽  
Rebecca M. Duffy ◽  
Ivan Batalov ◽  
Duco Kramer ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Disease Modeling ◽  
Contractile Function ◽  
Three Dimensional ◽  
Induced Pluripotent Stem Cell ◽  
Heart Tissue ◽  
Disease Phenotype ◽  
Heart Formation ◽  
Induced Pluripotent ◽  
And Function

The role that mechanical forces play in shaping the structure and function of the heart is critical to understanding heart formation and the etiology of disease but is challenging to study in patients. Engineered heart tissues (EHTs) incorporating human induced pluripotent stem cell (hiPSC)–derived cardiomyocytes have the potential to provide insight into these adaptive and maladaptive changes. However, most EHT systems cannot model both preload (stretch during chamber filling) and afterload (pressure the heart must work against to eject blood). Here, we have developed a new dynamic EHT (dyn-EHT) model that enables us to tune preload and have unconstrained contractile shortening of >10%. To do this, three-dimensional (3D) EHTs were integrated with an elastic polydimethylsiloxane strip providing mechanical preload and afterload in addition to enabling contractile force measurements based on strip bending. Our results demonstrated that dynamic loading improves the function of wild-type EHTs on the basis of the magnitude of the applied force, leading to improved alignment, conduction velocity, and contractility. For disease modeling, we used hiPSC-derived cardiomyocytes from a patient with arrhythmogenic cardiomyopathy due to mutations in the desmoplakin gene. We demonstrated that manifestation of this desmosome-linked disease state required dyn-EHT conditioning and that it could not be induced using 2D or standard 3D EHT approaches. Thus, a dynamic loading strategy is necessary to provoke the disease phenotype of diastolic lengthening, reduction of desmosome counts, and reduced contractility, which are related to primary end points of clinical disease, such as chamber thinning and reduced cardiac output.

scholarly journals Correction to: Mechanical and Volumetric Fracturing Behaviour of Three‑Dimensional Printing Rock‑like Samples Under Dynamic Loading

2020 ◽  
Author(s):  
Tao Zhou ◽  
Jianbo Zhu ◽  
·Heping Xie
Keyword(s):  
Dynamic Loading ◽  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Volumetric Fracturing ◽  
Dimensional Printing

The article Mechanical and Volumetric Fracturing Behaviour of Three-Dimensional Printing Rock-like Samples.

scholarly journals Effects of Different Positions and Angles of Implants in Maxillary Edentulous Jaw on Surrounding Bone Stress under Dynamic Loading: A Three-Dimensional Finite Element Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Xiaqing Liu ◽  
Fang Pang ◽  
Ying Li ◽  
Hui Jia ◽  
Xiaohua Cui ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Dynamic Loading ◽  
Three Dimensional ◽  
Element Analysis ◽  
Posterior Teeth ◽  
Dimensional Finite Element ◽  
Three Dimensional Models ◽  
Three Dimensional Finite Element ◽  
Edentulous Jaws ◽  
Surrounding Bone

Purpose. To evaluate the effects of different placements of mesial implants and different angles of distant implants in maxillary edentulous jaws on the stress on the implant and the surrounding bone tissue under dynamic loading. Materials and Methods. Cone beam computed tomography was used to acquire images of maxillary edentulous jaws. Using Mimics 17.0, Geomagic, and Unigraphics NX8.5 software, three-dimensional models were established: two mesial implants were placed vertically in the anterior region of the maxilla (bilateral central incisor, lateral incisor, and canine), and two distant implants were placed obliquely in the bilateral second premolar area at different inclined angles (15°, 30°, and 45°). The established models were designated I–IX. The models were subjected to dynamic load using Abaqus 6.12, with the working side posterior teeth loading of 150 N and simulation cycle of 0.875 s. Results. During the second to fourth phases of the mastication cycle, the stress was mainly concentrated on the neck of the distal implant. The stress of the distal implants was greater than that of mesial implants. Stress levels peaked in the third stage of the cycle. The stress of the distal cortical bone of distal implant of Model I reached the maximum of 183.437 MPa. The stress of the distal cortical bone and cancellous bone of distal implant of Model VIII represented the minima (62.989 MPa and 17.186 MPa, respectively). Conclusions. Our models showed optimal stress reductions when the mesial implants were located in the canine region and the distal implants tilted 30°.

scholarly journals Strength and Failure Characteristics of Natural and Water-Saturated Coal Specimens under Static and Dynamic Loads

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Wen Wang ◽  
Heng Wang ◽  
Dongyin Li ◽  
Huamin Li ◽  
Zhumeng Liu
Keyword(s):  
Dynamic Loading ◽  
Split Hopkinson Pressure Bar ◽  
Three Dimensional ◽  
Dynamic Strength ◽  
Hopkinson Pressure Bar ◽  
Static Compression ◽  
One Dimensional ◽  
Before And After ◽  
Loading Tests ◽  
Water Saturated

Rock bursts occur frequently in coal mines, and the mechanical properties of saturated coal specimens under coupled static-dynamic loading need to be studied in detail. Comparative tests of coal specimens having different water content under static and static-dynamic loading are conducted using the split Hopkinson pressure bar (SHPB) and RMT-150C test systems. The results demonstrate that the natural specimen strength is greater than that of seven-day (7D) saturated specimens under both uniaxial compression and triaxial static compression loading; however, the dynamic strength of 7D saturated specimens is lower than that of natural specimens under one-dimensional static-dynamic loading. The particle size of the 7D saturated specimens is relatively small under uniaxial static compression and one-dimensional static-dynamic loading, and the specimen particle sizes before and after static triaxial loading tests and three-dimensional static-dynamic loading tests do not exhibit an obvious difference.

Stress Distribution of the Variable Dynamic Loading in the Dental Implant: A Three-Dimensional Finite Element Analysis

2017 ◽  
Vol 31 ◽  
pp. 44-52 ◽  
Author(s):  
Noureddine Djebbar ◽  
B. Serier ◽  
Bel Abbès Bachir Bouiadjra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Loading ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Chewing Activity

Stable osseointegration between implant threads and the surrounding marginal bone provides the mechanical base of an implant for daily chewing activity. The contact area of implant-bone interfaces and the concentrated stresses on the marginal bones are principal concerns of implant designers. In this work we numerically analyze by the finite element method the distribution of the equivalent stress and their level in the bone the most fragile element of the dental prosthesis. Each set of the model contained a crown, framework, abutment, implant and bone, subjected to variable dynamic loading according to time.

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