Identification of the Dynamic Properties of Linear Joints Using Substructure Synthesis Method

2010 ◽  
Vol 44-47 ◽  
pp. 712-718
Author(s):  
Ling Li ◽  
Li Gang Cai ◽  
Tie Neng Guo ◽  
Zhi Feng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Properties ◽  
Synthesis Method ◽  
Joint Stiffness ◽  
Element Model ◽  
Substructure Synthesis ◽  
The Stability ◽  
Stiffness And Damping ◽  
Good Agreement

In this thesis, a new identification method for joint stiffness and damping has been developed by using the substructure synthesis method and finite element modeling. The substructure synthesis method is stated firstly, according to the substructures are connected by joints and the equilibrium and compatibility conditions at the joints have to be fulfilled, establishing identification equation through completely frequency response function. Then, finite element model is established, and update this model, make use of the update model to replace the experimental model, using an accurate finite element model to obtain the required data. In order to ensure the stability of the numerical calculation, translate inconsistent equation into the general solution through the principle of least squares, besides the introduction of the concept of weighted, makes the measured data can be fully utilized. Finally, the method is applied to a simulated example and good agreement is found between identified and true parameters.

Study on Modal Analysis for Motorcycle Frame by CAE Method

2014 ◽  
Vol 496-500 ◽  
pp. 601-604
Author(s):  
Jing Wang ◽  
Yong Wang ◽  
Ying Hua Liao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Experimental Method ◽  
Dynamic Properties ◽  
Element Model ◽  
Analytic Method ◽  
Motorcycle Frame ◽  
The Finite Element Model ◽  
Good Agreement

In this paper, the modal of motorcycle frame is analyzed by using the analytic method and experimental method. The results show that the dynamic properties of the finite element model are in good agreement with the experiment and the finite element model was reliable and accurate.

Research on seismic behavior of special-shaped CFST column to H-section steel beam joint

2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Joint Stiffness ◽  
Load Ratio ◽  
Element Model ◽  
Steel Tube ◽  
Steel Beam ◽  
Static Test

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.

Rigid-Plastic Impact of Single Angular Particles

2021 ◽  
Author(s):  
Sandeep Dhar
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Orientation Dependence ◽  
Particle Orientation ◽  
Rigid Plastic ◽  
Plastic Model ◽  
Model Predictions ◽  
Good Agreement ◽  
Angular Particles

The trajectory of an angular particle as it cuts a ductile target is, in general, complicated because of its dependence not only on particle shape, but also on particle orientation at the initial instant of impact. This orientation dependence has also made experimental measurement of impact parameters of single angular particles very difficult, resulting in a relatively small amount of available experimental data in the literature. The current work is focused on obtaining measurements of particle kinematics for comparison to rigid plastic model developed by Papini and Spelt. Fundamental mechanisms of material removal are identified, and measurements of rebound parameters and corresponding crater dimensions of single hardened steel particles launched against flat aluminium alloy targets are presented. Also a 2-D finite element model is developed and a dynamic analysis is performed to predict the erosion mechanism. Overall, a good agreement was found among the experimental results, rigid-plastic model predictions and finite element model predictions.

scholarly journals Modeling inflatable fabric with undevelopable surfaces by motion folding method

2019 ◽  
Vol 14 ◽  
pp. 155892501988640
Author(s):  
Xiao-Shun Zhao ◽  
He Jia ◽  
Zhihong Sun ◽  
Li Yu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Numerical Study ◽  
Technical Problem ◽  
Three Dimensional ◽  
Element Model ◽  
Model Errors ◽  
Folding Model ◽  
Study Results ◽  
The Stability

At present, most space inflatable structures are composed of flexible inflatable fabrics with complex undevelopable surfaces. It is difficult to establish a multi-dimensional folding model for this type of structure. To solve this key technical problem, the motion folding method is proposed in this study. First, a finite element model with an original three-dimensional surface was flattened with a fluid structure interaction algorithm. Second, the flattened surface was folded based on the prescribed motion of the node groups, and the final folding model was obtained. The fold modeling process of this methodology was consistent with the actual folding processes. Because the mapping relationship between the original finite element model and the final folding model was unchanged, the initial stress was used to modify the model errors during folding process of motion folding method. The folding model of an inflatable aerodynamic decelerator, which could not be established using existing folding methods, was established by using motion folding method. The folding model of the inflatable aerodynamic decelerator showed that the motion folding method could achieve multi-dimensional folding and a high spatial compression rate. The stability and regularity of the inflatable aerodynamic decelerator numerical inflation process and the consistency of the inflated and design shapes indicated the reliability, applicability, and feasibility of the motion folding method. The study results could provide a reference for modeling complex inflatable fabrics and promote the numerical study of inflatable fabrics.

Identification of Joint Parameters for a Taper Joint

1989 ◽  
Vol 111 (3) ◽  
pp. 282-287 ◽  
Author(s):  
T. R. Kim ◽  
S. M. Wu ◽  
K. F. Eman
Keyword(s):  
Finite Element ◽  
Experimental Verification ◽  
Joint Stiffness ◽  
Element Model ◽  
Damping Characteristics ◽  
Analysis Technique ◽  
Joint Parameters ◽  
Stiffness And Damping ◽  
Taper Joint ◽  
The Finite Element Model

A new methodology of combining the finite element model of a structure with the results of the experimental modal analysis technique was applied to a tool-holder system with a taper joint to identify its joint stiffness and damping characteristics. The underlying background is briefly introduced followed by an experimental verification of the proposed method.

Identification of Dynamic Rates of Elastomeric Vibration Isolators in Automotive Vehicles

2004 ◽  
Author(s):  
Donald J. Nefske ◽  
Shung H. (Sue) Sung ◽  
Douglas A. Feldmaier
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Stiffness ◽  
Element Model ◽  
Interior Noise ◽  
Rear Suspension ◽  
Model Comparisons ◽  
Vibration Isolators ◽  
Vehicle System ◽  
Stiffness And Damping

Dynamic stiffness and damping rates of elastomeric vibration isolators used in automotive vehicles are identified from static isolator tests and the use of an isolator finite element model. Comparisons are made of the predicted versus measured dynamic stiffness and damping rates from 0 to 300 Hz of a rear suspension isolator to validate the technique. The identified dynamic rates of the elastomeric isolators of a representative vehicle are then input to the vehicle system finite-element model to compare the predicted versus measured vehicle vibration and interior noise response for laboratory shaker excitation.

scholarly journals Analysis of Vibration of Roadheader Rotary Table Based on Finite Element Method and Data from Underground Coalmine

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Minjun Zhang ◽  
Fuyan Lyu ◽  
Xiushan Tang ◽  
Yang Yang ◽  
Xiaodong Ji ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Properties ◽  
Single Point ◽  
Element Model ◽  
Rotary Table ◽  
Cutting Head ◽  
Cutting System ◽  
The Finite Element Model ◽  
Intense Vibration

The intense vibration of a roadheader rotary table damages the cutting system of the roadheader and reduces the efficiency. This paper analyzes the vibration of a rotary table by combining the finite element model with tested data from an underground coalmine. First, the force of the rotary table during the cutting procedure was analyzed, and the finite element model was built using Pro/E and ADAMS. The tested data were then imported into the model after selection, procession, and combination were conducted. Next, the six lowest-order parameters of the rotary table were calculated. A vibration analysis of the rotary table under certain working conditions was conducted, and the results were compared with those from a modal experiment using a single-point excitation method. According to the comparison between the simulation result and experiments, it is clear that this method is both reasonable and feasible. And it could supplement the theoretical foundation of the analysis of other roadheader components, providing reference for the improvement of the structure and dynamic properties of a roadheader. In addition, other vibration components of a roadheader such as the cutting head and the cutting arm could also be analyzed through the proposed method, with very reliable precision.

Displacement Properties of Newly Developed 3-Dimensional Piezoelectric Actuator at Various AC Frequencies

2007 ◽  
Vol 534-536 ◽  
pp. 1441-1444 ◽  
Author(s):  
Man Soon Yoon ◽  
Y.G. Choi ◽  
Soon Chul Ur
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Piezoelectric Actuator ◽  
Element Model ◽  
Vibration Modes ◽  
Maximum Strain ◽  
Electromechanical Properties ◽  
3 Dimensional ◽  
The Finite Element Model ◽  
Good Agreement

The electromechanical properties of a newly proposed 3-dimensional piezoelectric actuator have been investigated. Especially, the effects of 3-dimensional geometry on the maximum tip displacement were carefully investigated. As a result, it was found that the maximum strain of the 3-dimensional piezoelectric device was significantly enhanced up to 4.5 times higher than that of a disk shape device. This data was in good agreement with the finite element model analysis of strains and vibration modes. Moreover, the field -induced displacement stability of dome-shaped 3- dimensional piezoelectric actuator at various ac freguencies was superior to Rainbow actuator.

Joint Stiffness of 3D Space Frame Thin Walled Structural Joint Considering Local Buckling Effect

2014 ◽  
Vol 660 ◽  
pp. 773-777
Author(s):  
Mohd Shukri Yob ◽  
Shuhaimi Mansor ◽  
Razali Sulaiman
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Joint Stiffness ◽  
Element Model ◽  
Joint Effect ◽  
Experimental Result ◽  
Space Frame ◽  
3D Space ◽  
Structural Joint ◽  
Thin Walled

Thin walled structure is widely used in designing light weight vehicle. For automotive industry, weight is an important characteristic to increase performance of a vehicle. Vehicle structures are built from thin walled beams by joining them using various joining methods and techniques. For a structure, its stiffness greatly depends on joint stiffness. However, stiffness of thin walled beam is difficult to predict accurately due to buckling effect. Once the beams are joined to form a structure, it will expose to joint flexibility effect. A lot of researches had been done to predict the behaviors of thin walled joint analytically and numerically. However, these methods failed to come out with satisfactory result. In this research work, finite element model for 3D space frame thin walled structural joint is developed using circular beam element by validating with experimental result. Another finite element model using rigid element is used to represent 3D space frame behavior without joint effect. The difference between these 2 models is due to joint effect. By using same modelling technique, joint stiffness for different sizes can be established. Then, the relation between joint stiffness for 3D space frame and size of beam can be obtained.

Updating of Finite Element Model in Considering Mode Errors with Fuzzy Theory

2009 ◽  
Vol 413-414 ◽  
pp. 785-792 ◽  
Author(s):  
Yang Liu ◽  
Zhong Dong Duan ◽  
Hui Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Fuzzy Theory ◽  
Dynamic Properties ◽  
Fuzzy Model ◽  
Element Model ◽  
Structural Dynamic ◽  
Fuzzy Variables ◽  
Design Variables

Finite element model updating aims at reconciling the analytical model with the test one, to acquire a refined model with high-fidelity in structural dynamic properties. However, testing data are inevitable polluted by noises. In this study, the mode parameters and design variables are modeled as fuzzy variables, and a fuzzy model updating method is developed. Instead of a single optimal model, a set of satisfactory models is obtained. The most physically compatible solution is sorted by insights to the structures. The proposed method is applied to a real concrete bridge, for which a physically meaningful model is identified.

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