Fracture Evaluation of the Falling Weight Impact Behaviour of a Basalt/Vinylester Composite Plate through a Multiphase Finite Element Model

2017 ◽  
Vol 754 ◽  
pp. 59-62 ◽  
Author(s):  
Felipe Vannucchi de Camargo ◽  
Ana Pavlovic
Keyword(s):  
Finite Element ◽  
Natural Fibers ◽  
Fem Simulation ◽  
Experimental Tests ◽  
Element Model ◽  
Multiphase Model ◽  
Low Velocity ◽  
Weight Impact ◽  
The One ◽  
Falling Weight

Several investigations regarding the mechanical behaviour of composites reinforced by natural fibers under impact have been realized recently, aiming at achieve a low-weight and resistant design. At the same time, progressively accurate results on numerical simulations have been reached powered by modern Finite Element Method (FEM) approaches for composites; however, demonstrating a faithful indentation pattern is still a challenge. The present work aims at building an impact numerical simulation that exhibits a fracture mechanism exactly like the one seen in experimental tests, also carried in this work, on a Basalt Reinforced Composite Polymer (BRFP) plate subjected to low-velocity falling weight impact (IFW). The FEM simulation describes a multiphase model considering each ply and their inter-layer interactions.

scholarly journals Possible reasons for early artificial bone failure in biomechanical tests of ankle arthrodesis systems

2015 ◽  
Vol 1 (1) ◽  
pp. 507-509
Author(s):  
H. Martin ◽  
N. Gutteck ◽  
J.-B. Matthies ◽  
T. Hanke ◽  
G. Gradl ◽  
...  
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Experimental Tests ◽  
Element Model ◽  
Ankle Arthrodesis ◽  
Artificial Bone ◽  
Basic Model ◽  
Simplified Finite Element Model ◽  
Biomechanical Tests ◽  
Horizontal Displacements

AbstractIn order to demonstrate the influence of the boundary conditions in experimental biomechanical investigations of arthrodesis implants two different models were investigated. As basic model, a simplified finite element model of the cortical bone was used in order to compare the stress values with (Model 1) and without (Model 2) allowing horizontal displacements of the load application point. The model without constraints of horizontal displacements showed considerably higher stress values at the point of failure. Moreover, this investigation shows that the boundary conditions (e.g. constraints) have to be carefully considered, since simplifications of the reality with experimental tests cannot always be avoided.

Rotordynamics Analysis: Experimental and Numerical Investigations

2003 ◽  
Author(s):  
Jean-Jacques Sinou ◽  
David Demailly ◽  
Cristiano Villa ◽  
Fabrice Thouverez ◽  
Michel Massenzio ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Critical Speed ◽  
Experimental Tests ◽  
Element Model ◽  
Test Rig ◽  
Turbofan Engine ◽  
Rotating Structure ◽  
Vibration Problems ◽  
The Finite Element Model

This paper presents a research devoted to the study of vibration problems in turbofan application. Several numerical and experimental tools have been developed. An experimental test rig that simulates the vibrational behavior of a turbofan engine is presented. Moreover, a finite element model is used in order to predict the non-linear dynamic behavior of rotating machines and to predict the first critical speed of engineering machine. A comparison between the experimental tests and the numerical model is conducted in order to evaluate the critical speed of the rotating structure and to update the finite element model.

scholarly journals Torsional Behaviour and Finite Element Analysis of the Hybrid Laminated Composite Shafts: Comparison of VARTM with Vacuum Bagging Manufacturing Method

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Mehmet Emin Taşdelen ◽  
Mehmet Halidun Keleştemur ◽  
Ercan Şevkat
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Glass Fibers ◽  
Laminated Composite ◽  
Experimental Tests ◽  
Element Model ◽  
Performance Criteria ◽  
Fiber Types ◽  
Element Analysis ◽  
Manufacturing Method

Braided sleeve composite shafts are produced and their torsional behavior is investigated. The braided sleeves are slid over an Al tube to create very strong and rigid tubular form shafts and they are in the form of 2/2 twill biaxial fiber fabric that has been woven into a continuous sleeve. Carbon and glass fibers braided sleeves are used for the fabrication of the composite shafts. VARTM (vacuum assisted resin transfer molding) and Vacuum Bagging are the two different types of manufacturing methods used in the study. Torsional behaviors of the shafts are investigated experimentally in terms of fabrication methods and various composite materials parameters such as fiber types, layer thickness, and ply angles. Comparing the two methods in terms of the torque forces and strain angles, the shafts producing entirely carbon fiber show the highest torque capacities; however, considering the cost and performance criteria, the hybrid shaft made up of carbon and glass fibers is the optimum solution for average demanded properties. Additionally, FE (finite element) model of the shafts was created and analyzed by using ANSYS workbench environment. Results of finite element analysis are compared with the values of twisting angle and torque obtained by experimental tests.

FEM Simulation of Anisotropic Parameters Influencing the Earing in Sheet Metal Deep Drawing Process

2011 ◽  
Vol 88-89 ◽  
pp. 638-641 ◽  
Author(s):  
Lei Chen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Sheet Metal ◽  
Deep Drawing ◽  
Fem Simulation ◽  
Element Model ◽  
Drawing Process ◽  
Deep Drawing Process ◽  
Material Characteristics

Earing is often undesirable in the production of deep drawn containers because it results in a nonuniform cup height. A finite element model for earring analysis is developed considering only the flange area of the sheet. It was found that the draw-in depth of the flange increases with the increase of the r value, and it remains invariable when r value is larger than 2. With the increase of the r value, the max thickness decreases and the min thickness increases. If △r>0, four earings are formed. If △r =0, the material characteristics in all the planar directions are same. The flange uniformly flows into the die cavity, no earing is formed. If △r<0, four earings are formed. The earing distribution is dominated by r0, r45 and r90. Both r and △r have much effect on the earing distribution.

scholarly journals Influence Factors Analysis of RC Beams under Falling Weight Impact Based on HJC Model

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Xiaohong Long ◽  
Ahmed Turgun ◽  
Rong Yue ◽  
Yongtao Ma ◽  
Hui Luo
Keyword(s):  
Finite Element ◽  
Impact Load ◽  
Influence Factors ◽  
Response Analysis ◽  
Impact Loads ◽  
Rc Beams ◽  
Element Analysis ◽  
Structure Component ◽  
Weight Impact ◽  
Falling Weight

Impact loads may cause serious or even fatal damage to the structure (component), in most existing specifications in China, and there are no special terms that take impact load into consideration. So, the response analysis of the structure (component) under impact loads is very important. In this paper, the sensitivity analysis was conducted for the 22 parameters of the Holmquist–Johnson concrete (HJC) constitutive model of concrete, and the sensitive parameters of the HJC model are identified with A, B, G, Pl, μl, and fc respectively. LS-DYNA nonlinear transient finite element analysis code was used for this paper. Based on the validation of finite element modeling and choosing midspan deflection of RC beams and impact loads as response indices, some influencing factors on RC beams under falling weight impact were investigated, such as the mass and speed of falling weight, impact position, the strength of concrete and rebar, longitudinal reinforcement ratio, and the span of the beam.

scholarly journals NUMERICAL ANALYSIS OF GLULAM BEAMS REINFORCED WITH CFRP PLATES

2017 ◽  
Vol 23 (7) ◽  
pp. 868-879 ◽  
Author(s):  
Ivan GLIŠOVIĆ ◽  
Marko PAVLOVIĆ ◽  
Boško STEVANOVIĆ ◽  
Marija TODOROVIĆ
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Experimental Tests ◽  
Element Model ◽  
Elastic Stiffness ◽  
Anisotropic Plasticity ◽  
Stress Criterion ◽  
Cfrp Plate ◽  
Reinforced Beams ◽  
Glued Laminated Timber

This paper presents an analysis of bending behaviour of glued laminated timber (glulam) beams reinforced with carbon fibre reinforced polymer (CFRP) plates, based on finite element numerical modelling. Nonlinear 3-dimen­sional model was developed and validated by experimental tests carried out on unreinforced beams and beams reinforced with two different reinforcement arrangements. Suitable constitutive relationships for each material were utilised in the model, as well as anisotropic plasticity theory for timber in compression. Adhesive bond between CFRP plate and timber was modelled as a perfect connection. Beam failure in the model was defined by maximum stress criterion. The predicted behaviour of beams has shown good agreement with the experimental results in relation to load-deflection relationship, ultimate load, elastic stiffness and strain profile distribution. The non-linear behaviour of reinforced beams before failure was also achieved in the numerical analysis, confirming the finite element model to be accurate past the linear-elastic range. Experimentally tested reinforced beams usually failed in tensile zone after compressive plasticiza­tion of top lamination, which was also simulated in the numerical model. The results proved that the load carrying ca­pacity, stiffness and ductility of glulam beams were successfully increased by addition of CFRP plate at tension side of the section.

Elastodynamic and finite element vibration analysis of a drillstring with a downhole vibration generator tool and a shock sub

2014 ◽  
Vol 229 (8) ◽  
pp. 1361-1384 ◽  
Author(s):  
Ahmad Ghasemloonia ◽  
D Geoff Rideout ◽  
Stephen D Butt ◽  
Ali Hajnayeb
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Vibration Suppression ◽  
Fem Simulation ◽  
Element Model ◽  
Hertzian Contact ◽  
Contact Points ◽  
Fast Running ◽  
Lateral Displacements ◽  
Dynamic Amplification

Applying high-frequency axial oscillation into an oilwell drillstring in the “bottom-hole assembly” (BHA) has the potential to enhance drilling efficiency in extended reach wells. Downhole vibration generator tools such as agitators reduce the drillstring–wellbore friction and enhance the rate of penetration. However, introducing controlled vibrations into the drillstring can result in undesired vibration waves propagating along the drillstring, leading to inefficient drilling and catastrophic fatigue failure of the BHA components, “measurement-while-drilling” tools, and mud motors. A dynamic model of the entire drillstring, including vibration generators and shock subs, is required to study the effect of vibration generators on the complex nonlinear coupled axial-lateral dynamics of a drillstring inside a wellbore, to study the effect of vibration tools on the developed cutting force at the bit, and to facilitate simulation-based design of shock subs. A dynamic finite element model (FEM) and an analytical elastodynamic model, both including the vibration generator tool and a shock sub, have been developed. The “Bypassing PDEs” method was implemented on the Lagrangian of the system to develop the analytical equations. A multi-mode expanded Galerkin’s approximation, in conjunction with a multi-span BHA and Hertzian contact assumption, allowed analysis of multiple BHA contact points and, thus, more realistic estimates of drilling rotary speeds that can cause excessive vibration. The models also include torque, mud damping, spatially varying axial force, geometric nonlinearity, and axial stiffening. While the analytical model has fast running time and symbolic solution, the FEM model enables easy reconfiguration and future extensions of model geometry, interactions, and modified BHA configurations. There is agreement between the analytical and FEM simulation results for the vibration suppression ability of the shock sub, dynamic amplification of the vibrating tool force, critical rotary speeds, axial force along the drillstring, axial and lateral displacements, and the contact locations and severity.

Nonlinear Finite Element Analysis of a Threaded Pipe Connection

2004 ◽  
Author(s):  
Farzad Tasbihgoo ◽  
John P. Caffrey ◽  
Sami F. Masri
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Tests ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Mitigation Measures ◽  
Element Analysis ◽  
Nonstructural Components ◽  
Small Water ◽  
Threaded Connections

For the past several years, USC has been involved in a major research project to study the seismic mitigation measures of nonstructural components in hospitals funded by the Federal Emergency Management Agency (FEMA). It was determined that piping was the one of the most critical components affecting the functionality of a hospital following an earthquake. Consequently, a substantial effort was spent on quantifying the behavior of typical piping components. During the loading of the threaded joint, it was common to hear a loud popping sound, followed by a small water leak. It was assumed that the sound and leakage were due to the sliding of the mating pipe threads. To confirm this theory, and to provide a tool to help understand the failure mode(s) for a wide class of threaded fittings, a detailed nonlinear finite element model was constructed using MSC/NASTRAN, and correlated to the measured failures. In this paper, a simplified model is presented first to demonstrate the modeling procedure and to help understand the sliding phenomenon. Next, a symmetric half 3D model was generated for modeling the physical experiments. It is shown that the finite element analysis (FEA) of the threaded connections captures the dominant mechanism that was observed in the experimental tests.

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