scholarly journals Micromechanical Behavior of Single-Crystal Superalloy with Different Crystal Orientations by Microindentation

2015 ◽  
Vol 2015 ◽  
pp. 1-15
Author(s):  
Jinghui Li ◽  
Fuguo Li ◽  
Junzhe Dong ◽  
Zhanwei Yuan ◽  
Shuo Zhang
Keyword(s):  
Single Crystal ◽  
Interplanar Spacing ◽  
Plastic Material ◽  
Material Model ◽  
Material Parameters ◽  
Nickel Based Superalloy ◽  
Crystal Orientations ◽  
Dislocation Hardening ◽  
Simulation Results ◽  
Elastic Plastic Material

In order to investigate the anisotropic micromechanical properties of single-crystal nickel-based superalloy DD99 of four crystallographic orientations, (001), (215), (405), and (605), microindentation test (MIT) was conducted with different loads and loading velocities by a sharp Berkovich indenter. Some material parameters reflecting the micromechanical behavior of DD99, such as microhardnessH, Young’s modulusE, yield stressσy, strain hardening componentn, and tensile strengthσb, can be obtained from load-displacement relations.HandEof four different crystal planes evidently decrease with the increase ofh. The reduction ofHis due to dislocation hardening whileEis related to interplanar spacing and crystal variable.σyof (215) is the largest among four crystal planes, followed by (605), and (001) has the lowest value.nof (215) is the lowest, followed by (605), and that of (001) is the largest. Subsequently, a simplified elastic-plastic material model was employed for 3D microindentation simulation of DD99 with various crystal orientations. The simulation results agreed well with experimental, which confirmed the accuracy of the simplified material model.

A Continued Evaluation of the Role of Material Hardening Behavior for the NeT TG1 and TG4 Specimens

2014 ◽  
Author(s):  
David J. Dewees ◽  
Phillip E. Prueter ◽  
Seetha Ramudu Kummari
Keyword(s):  
Structural Integrity ◽  
Plastic Material ◽  
Critical Factor ◽  
Material Model ◽  
Standard Test ◽  
Material Behavior ◽  
Weld Residual Stress ◽  
Hardening Models ◽  
Elastic Plastic Material

Modeling of cyclic elastic-plastic material behavior (hardening) has been widely identified as a critical factor in the finite element (FE) simulation of weld residual stresses. The European Network on Neutron Techniques Standardization for Structural Integrity (NeT) Project has provided in recent years both standard test cases for simulation and measurement, as well as comprehensive material characterization. This has allowed the role of hardening in simulation predictions to be isolated and critically evaluated as never before possible. The material testing information is reviewed, and isotropic, nonlinear kinematic and combined hardening models are formulated and tested. Particular emphasis is placed on material model selection for general fitness-for-service assessments, as it relates to the guidance for weld residual stress (WRS) in flaw assessments of in-service equipment in Annex E of the FFS standard, API 579-1/ASME FFS-1.

Experiment and Elastic-Plastic Modelling of the IPN160 Beam

2015 ◽  
Vol 769 ◽  
pp. 331-335
Author(s):  
Jakub Vasek ◽  
Oldrich Sucharda
Keyword(s):  
Computational Models ◽  
Plastic Material ◽  
Numerical Models ◽  
Steel Structure ◽  
Material Model ◽  
Nonlinear Material ◽  
Software Application ◽  
Elastic Plastic ◽  
Elastic Plastic Material ◽  
Isoparametric Finite Elements

The paper compares the numerical models of and experiments with a beam. The purpose is to evaluate the nonlinear material model of a steel structure. The steel is modelled as an ideal elastic-plastic material. The FEM and eight-node isoparametric finite elements are considered in the analysis. The 3D calculations use different material constants and several approaches are being tested in order to create the computational models. The calculations are performed in the software application developed by our university.

Reducing Occupant Injury in Frontal Crashes for a Low-Floor City Bus

2005 ◽  
Author(s):  
Elham Sahraei Esfahani ◽  
Kurosh Darvish ◽  
Mohamad Parnianpour ◽  
Akbar Bateni
Keyword(s):  
Plastic Material ◽  
Material Model ◽  
Element Model ◽  
Driver Model ◽  
City Bus ◽  
Hybrid Iii ◽  
Occupant Injury ◽  
Occupant Injuries ◽  
Frontal Crashes ◽  
Elastic Plastic Material

In this research, the effect of beam buckling in a predefined direction is used to reduce occupant injuries in frontal crashes of an ultra-low-floor (ULF) city bus. In ULF buses, the floor structure consists of several longitudinal long beams, which in case of a frontal crash may buckle due to the axial impact. The direction of rotational acceleration of the driver seat due to buckling is highly affected by the position of the driver seat. A finite element model of an ULF bus was developed using LS-Dyna. The driver model, a Hybrid III 50th male dummy with deformable jacket and abdomen, was restrained to the seat with a 3-point belt. An Elastic-Plastic material model was used for the bus structure to investigate the buckling behavior of the beam elements. Using diagonal beams to guide the buckling in a desired direction, rewarding results were achieved in reducing the occupant injuries. For example, with an extra diagonal beam under the seat, the driver’s HIC15 was reduced from 739 to 415.7 and HIC36 from 791 to 700.6.

Study on Impinging Stream Flow Channel in Abrasive Flow Polishing Complex Cavity of Precision Mold

2013 ◽  
Vol 797 ◽  
pp. 469-474
Author(s):  
Di Feng Zhou ◽  
Dong Yu Liu
Keyword(s):  
Stream Flow ◽  
Plastic Material ◽  
Material Model ◽  
Impact Deformation ◽  
Element Simulation ◽  
Complex Cavity ◽  
Elastic Plastic Material ◽  
Set Up ◽  
The Impact ◽  
Abrasive Flow Polishing

In order to solve the problem about polishing complex cavity of precision mold, to improve the efficiency of processing and reduce the surface roughness, putting forward multiple entries impinging stream processing device.With making use of the collision of two strands of abrasive flow, Realizing the mutual disturbance of abrasive flow in the runner, and increasing the collision between abrasive to improve the disordering of abrasive movement, for promoting abrasive polishing to mold cavity. Johnson-Cook elastic-plastic material model is set up at the same time, using abaqus finite element simulation to simulate the impact deformation wear and cutting wear with the increasment of impact times.

Calibration of Elastic-Plastic Material Model for Tire Shreds

2004 ◽  
Author(s):  
Boris Jeremić ◽  
James Putnam ◽  
Kallol Sett ◽  
Dana Humphrey ◽  
Stacey Patenaude
Keyword(s):  
Plastic Material ◽  
Material Model ◽  
Elastic Plastic ◽  
Tire Shreds ◽  
Elastic Plastic Material

Wrinkling of an Unevenly Stretched Sheet Metal

1989 ◽  
Vol 111 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Xiaofang Wang ◽  
L. H. N. Lee
Keyword(s):  
Finite Element Method ◽  
Sheet Metal ◽  
Strong Influence ◽  
Flexural Rigidity ◽  
Plastic Material ◽  
Yield Function ◽  
Material Parameters ◽  
Varying Thickness ◽  
Anisotropic Yield Function ◽  
Elastic Plastic Material

The onset of wrinkling of an unevenly stretched sheet metal subject to finite deformation is analyzed by an incremental finite element method. The sheet metal is modeled as a plate made of an elastic-plastic material. Hill’s anisotropic yield function and bifurcation criterion are employed in the analysis. The effects of geometrical and material parameters upon the onset of wrinkling are investigated. In the bifurcation analysis, attention is given to the changing and varying thickness of the sheet metal which could have a strong influence on the flexural rigidity of the sheet. Numerical results are presented herein.

scholarly journals Nonlinear Modeling and Identification of an Aluminum Honeycomb Panel with Multiple Bolts

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yongpeng Chu ◽  
Hao Wen ◽  
Ti Chen
Keyword(s):  
Thin Layer ◽  
Plastic Material ◽  
Experimental Tests ◽  
Bolted Joints ◽  
High Excitation ◽  
Material Parameters ◽  
Elastic Plastic ◽  
Aluminum Honeycomb ◽  
Elastic Plastic Material ◽  
Honeycomb Panel

This paper focuses on the nonlinear dynamics modeling and parameter identification of an Aluminum Honeycomb Panel (AHP) with multiple bolted joints. Finite element method using eight-node solid elements is exploited to model the panel and the bolted connection interface as a homogeneous, isotropic plate and as a thin layer of nonlinear elastic-plastic material, respectively. The material properties of a thin layer are defined by a bilinear elastic plastic model, which can describe the energy dissipation and softening phenomena in the bolted joints under nonlinear states. Experimental tests at low and high excitation levels are performed to reveal the dynamic characteristics of the bolted structure. In particular, the linear material parameters of the panel are identified via experimental tests at low excitation levels, whereas the nonlinear material parameters of the thin layer are updated by using the genetic algorithm to minimize the residual error between the measured and the simulation data at a high excitation level. It is demonstrated by comparing the frequency responses of the updated FEM and the experimental system that the thin layer of bilinear elastic-plastic material is very effective for modeling the nonlinear joint interface of the assembled structure with multiple bolts.

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