scholarly journals Design of an Inkjet-Printed Rotary Bellows Actuator and Simulation of its Time-Dependent Deformation Behavior

2021 ◽  
Vol 8 ◽  
Author(s):  
Gabriel Dämmer ◽  
Michael Lackner ◽  
Sonja Laicher ◽  
Rüdiger Neumann ◽  
Zoltán Major
Keyword(s):  
Finite Element ◽  
Deformation Behavior ◽  
Materials Science ◽  
Three Dimensional ◽  
Material Model ◽  
Relaxation Experiment ◽  
State Of Stress ◽  
Complex Structural ◽  
Actuator Design

State-of-the-art Additive Manufacturing processes such as three-dimensional (3D) inkjet printing are capable of producing geometrically complex multi-material components with integrated elastomeric features. Researchers and engineers seeking to exploit these capabilities must handle the complex mechanical behavior of inkjet-printed elastomers and expect a lack of suitable design examples. We address these obstacles using a pneumatic actuator as an application case. First, an inkjet-printable actuator design with elastomeric bellows structures is presented. While soft robotics research has brought forward several examples of inkjet-printed linear and bending bellows actuators, the rotary actuator described here advances into the still unexplored field of additively manufactured pneumatic lightweight robots with articulated joints. Second, we demonstrate that the complex structural behavior of the actuator’s elastomeric bellows structure can be predicted by Finite Element (FE) simulation. To this end, a suitable hyperviscoelastic material model was calibrated and compared to recently published models in a multiaxial-state-of-stress relaxation experiment. To verify the material model, Finite Element simulations of the actuator’s deformation behavior were conducted, and the results compared to those of corresponding experiments. The simulations presented here advance the materials science of inkjet-printed elastomers by demonstrating use of a hyperviscoelastic material model for estimating the deformation behavior of a prototypic robotic component. The results obtained contribute to the long-term goal of additively manufactured and pneumatically actuated lightweight robots.

scholarly journals Long-Term Settlement of High Concrete-Face Rockfill Dam by Field Monitoring and Numerical Simulation

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xinjie Zhou ◽  
Xinjian Sun ◽  
Junxing Zheng ◽  
Haoyuan Jiang ◽  
Yongye Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Creep Deformation ◽  
Deformation Behavior ◽  
Finite Element Software ◽  
Rockfill Materials ◽  
Stress And Deformation ◽  
Long Term Performance ◽  
Term Performance ◽  
Concrete Face

High concrete-face rockfill dams (CFRDs) with heights of over 100 m have been quickly developed in recent years. The self-weight of rockfill materials causes creep deformation of the dam body. However, the creep analysis method of high CFRDs in finite element software is few, and sometimes, it can also not reflect the long-term performance of high CFRDs well. Therefore, it is necessary to carry out the secondary development in finite element software. This study developed a subroutine that can run in Finite Element Method (FEM) platform ABAQUS to simulate long-term creep deformation behavior of the rockfill materials more accurately. Then, a displacement back-analysis for parameters, based on the Xujixia high CFRD project, is performed by the neural network response surface method (BP-MPGA/MPGA). Remarkable agreements are observed between simulation and field monitoring results. The calibrated FEM model is used to predict stress and deformation behavior of the Xujixia high CFRD after three years of operation period. The result indicates that rockfill creep deformation has a significant impact on stress and deformation of the high CFRD during the operation. This research may predict long-term performance using FEM in the design stage for high CFRDs.

scholarly journals Hot Workability of Ultra-Supercritical Rotor Steel Using a 3-D Processing Map Based on the Dynamic Material Model

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4118
Author(s):  
Xuewen Chen ◽  
Yuqing Du ◽  
Tingting Lian ◽  
Kexue Du ◽  
Tao Huang
Keyword(s):  
Finite Element ◽  
Alloy Steel ◽  
Thermal Processing ◽  
Processing Map ◽  
Three Dimensional ◽  
Material Model ◽  
Strain Rates ◽  
Rotor Steel ◽  
Dynamic Material Model ◽  
Finite Element Software

As a new-type of ultra-supercritical HI-IP rotor steel, X12CrMoWVNbN10-1-1 alloy steel has excellent integrative performance, which can effectively improve the power generation efficiency of the generator set. In this paper, uniaxial thermal compression tests were carried out over a temperature range of 950–1200 °C and strain rates of 0.05–5 s−1 with a Gleeble-1500D thermal simulation testing machine. Moreover, based on hot compression experimental data and the theory of processing diagrams, in combination with the dynamic material model, a three-dimensional (3-D) thermal processing map considering the effect of strain was constructed. It was concluded that optimum thermal deformation conditions were as follows: the temperature range of 1150–1200 °C, the strain rate range of 0.05–0.634 s−1. Through secondary development of the finite element (FE) software FORGE®, three-dimensional thermal processing map data were integrated into finite element software FORGE®. The distributions of instability coefficient and power dissipation coefficient were obtained over various strain rates and temperatures of the Ø 8 × 12 mm cylinder specimen by using finite element simulation. It is shown that simulation results are consistent with the microstructure photos. The method proposed in this paper, which integrates the three-dimensional processing map into the finite element software FORGE® (Forge NxT 2.1, Transvalor, Nice, France), can effectively predict the formability of X12CrMoWVNbN10-1-1 alloy steel.

Finite Element Analysis of a Steady-State Rotating Tire Subjected to Point Load or Ground Contact

1987 ◽  
Vol 15 (4) ◽  
pp. 243-260 ◽  
Author(s):  
R. Kennedy ◽  
J. Padovan
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Contact Point ◽  
Three Dimensional ◽  
Static Problem ◽  
Material Model ◽  
Point Load ◽  
Ground Contact ◽  
Element Analysis ◽  
Automobile Tire

Abstract A radial automobile tire undergoing steady-state rotation is analyzed by a finite element method. A special formulation is used which allows the finite element equations to be solved as a quasi-static problem using static analysis solution procedures, rather than as a dynamic problem requiring solution in the time domain. This is accomplished through a transformation of variable that changes time derivatives, present through inertia, to spatial derivatives. Solution time for the analysis is thereby shortened. The tire is modeled first as a two-dimensional ring on an elastic foundation, then in its full three-dimensional geometry. Rotational speeds are those at which resonance occurs so that the dynamics can be easily visualized and the response easily verified. The models are subjected to point load excitation or ground contact. Point load is used to predict resonance responses of the undamped tire. Results agreed well with experimental measurements. The effect of inertia components and damping on vibrational response of the tire was studied by imposing ground contact at one of the resonance speeds. Damping is included in the model through a two-element Kelvin-Voight viscoelastic material model. Responses of the models were similar to standing wave deformations in a tire.

3-D Finite Element Simulation of the Vertical-Horizontal Rolling Process

2010 ◽  
Vol 145 ◽  
pp. 187-192 ◽  
Author(s):  
Jin Hua Ruan ◽  
Li Wen Zhang ◽  
Chong Xiang Yue ◽  
Sen Dong Gu ◽  
Wen Bin He ◽  
...  
Keyword(s):  
Finite Element ◽  
Deformation Behavior ◽  
Metal Flow ◽  
Three Dimensional ◽  
Rolling Process ◽  
Shape Evolution ◽  
Rigid Plastic ◽  
Coupling Analysis ◽  
Mechanical Coupling ◽  
Element Simulation

In order to investigate the deformation behavior of a plate during a vertical-horizontal rolling process, a thermo-mechanical coupling analysis is carried out by three-dimensional (3-D) rigid-plastic FEM to simulate the process. The metal flow and the shape evolution of the plate are focused during this investigation. The thickness and the width of the plate agree well with the measured values.

3D Characterisation of Grain Deformation under Synchrotron Radiation

2010 ◽  
Vol 654-656 ◽  
pp. 2303-2306
Author(s):  
Masakazu Kobayashi ◽  
Hiroyuki Toda ◽  
Kentaro Uesugi ◽  
Akihisa Takeuchi ◽  
Yoshio Suzuki
Keyword(s):  
Synchrotron Radiation ◽  
Deformation Behavior ◽  
Strain Distribution ◽  
Materials Science ◽  
Tensile Deformation ◽  
Three Dimensional ◽  
Polycrystalline Aluminum ◽  
Science Field ◽  
Orientation Mapping ◽  
Observation Method

Recently, three-dimensional (3D) observation and analysis have attracted considerable attention in materials science field. By using the synchrotron radiation, the tomography makes possible high-resolution 3D observation dynamically and the recent diffraction analysis is available for 3D orientation mapping. In this study, grain deformation behavior in polycrystalline aluminum alloy has been characterized by 3D observation method applying the synchrotron radiation. The method to measure inner strain distribution by means of microstructural features tracking provides strain distribution within the sample, which we could not access before. The effect of grain orientation and its interaction during tensile deformation was discussed with the obtained strain distribution.

Research on Ultrasonic Shot Peening through Numerical Simulation

2015 ◽  
Vol 778 ◽  
pp. 59-62 ◽  
Author(s):  
Yan Jun Fan ◽  
Xiao Hui Zhao
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Shot Peening ◽  
Three Dimensional ◽  
Material Model ◽  
Simulation Method ◽  
Strengthening Mechanism ◽  
Mechanical Parts ◽  
Element Simulation ◽  
Ultrasonic Shot Peening

Ultrasonic shot peening can be used to strengthen mechanical parts. Its equipment structure is compact, which is convenient for incorporated into production line. It is fitting to facilitate operation and high reproducibility without dust pollution and noise. The finite element simulation method of ultrasonic shot peening further contributes to the development of ultrasonic shot peening technology. In the present work, finite element simulation method was adopted to establish a three-dimensional numerical model for analyzing the strengthening mechanism of ultrasonic shot peening. By choosing reasonable material model and different combination of parameters (such as treated material, diameter of shots, peening velocity), the curves of residual stress vs. depth of alloy materials were obtained, including the relationships between the peak value and depth of residual compression stress and peening velocity.

scholarly journals Identification of the Constitutive Model Parameters by Inverse Optimization Method and Characterization of Hot Deformation Behavior for Ultra-Supercritical Rotor Steel

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1958
Author(s):  
Xuewen Chen ◽  
Yuqing Du ◽  
Kexue Du ◽  
Tingting Lian ◽  
Bingqi Liu ◽  
...  
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Deformation Behavior ◽  
Material Model ◽  
Optimization Method ◽  
Resistant Steel ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Heat Resistant Steel ◽  
Heat Resistant

X12 (X12CrMoWVNbN10-1-1) ferritic heat resistant steel is an important material for the production of new-generation ultra-supercritical generator rotors. Hot compression tests of X12 ferritic heat-resistant steel were performed via a Gleeble-1500D testing machine under temperatures of 1050–1250 °C and strain rates of 0.05–5 s−1. In order to provide material model data for finite element simulations and accurately predict the hot deformation behavior, a reverse optimization method was proposed to construct elevated temperature constitutive models of X12 ferritic heat-resistant steel in this paper, according to the Hansel–Spittel constitutive model. To verify the accuracy of the model, the predicted and experimental values of the constitutive model were compared. The results indicated that the model had a high prediction accuracy. Meanwhile, the correlation coefficient between the experimental value and the predicted value of constitutive model was 0.97833. For further verification of the accuracy of the model, it was implemented in finite element FORGE@ software to simulate the compression tests of different samples under different conditions. Comparing actual displacement–load curves with displacement–load curves acquired through finite element simulations, the results indicated that displacement–load curves predicted by the model were very consistent with actual displacement–load curves, which verified the accuracy of the model. Moreover, to research the optimal processing parameters of the material, hot processing maps were drawn according to the dynamic material model. In terms of microstructure evolution, a characteristic area distribution map of the hot processing map was established. Therefore, the optimal hot forming parameters regions were in the range of 1150–1200 °C/0.05–0.62 s−1 for X12 ferritic heat-resistant steel.

scholarly journals Finite element model of bamboo culm (Phyllostachys sp.) and its comparison to two experimental tests

2010 ◽  
Vol 58 (1) ◽  
pp. 153-160
Author(s):  
Václav Sebera ◽  
Jan Tippner ◽  
Petr Horáček ◽  
Aleš Dejmal ◽  
Martin Beníček
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Material Model ◽  
Element Model ◽  
Parametric Models ◽  
Bending Test ◽  
Bamboo Culm ◽  
Culm Wall

The main goal of the work was to build up a general parametric finite-element model of a bamboo culm in ANSYS computational system. Subsequently the model was compared to a experimental measurements of chosen mechanical properties – three point bending test and brasil test. A pa­ra­me­ter being compared was a force, which is necessary to exert to deform a sample on given strain. In this work two parametric models were created. First one is including dividing barrier – diaphragm. A mesh of the culm wall is mapped and is divided into three layers with different orthotropic material models in cylindrical coordinate system with respect to the culm axis. By contrast the barrier – diaphragm – is represented by free mesh with isotropic material model. Both FE models are fully parametric and three-dimensional. Hence they are very well utilizable for both further research of the bamboo itself and constructions from it.

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