Extended Nonlinear Analysis of Exactly-Constrained Compliant Compound Parallelogram Mechanisms

2015 ◽  
Author(s):  
Guangbo Hao ◽  
Haiyang Li ◽  
George Joseph
Keyword(s):  
Nonlinear Analysis ◽  
Axial Force ◽  
Thermal Effects ◽  
Nonlinear Finite Element ◽  
Element Analysis ◽  
Motion Direction ◽  
Modal Frequency ◽  
Primary Motion ◽  
Axial Forces ◽  
Forced Excitation

Extended nonlinear analysis of compliant compound parallelogram mechanisms is conducted in this paper. The analytical nonlinear model of a compound basic parallelogram mechanism (CBPM) is first derived incorporating the initial internal axial force. The stiffness equations of compound multi-beam parallelogram mechanisms (CMPMs) are then followed. The effect of initial internal axial forces on the primary motion is further analyzed, which can be employed to consider active displacement preloading control and thermal effects etc. It is shown that negative initial internal axial force will reduce the primary stiffness, and vice versa. The criteria for which the primary stiffness may be considered “constant” is defined and the initial internal axial force driven by temperature change is also formulated. The dynamic analysis of a CMPM using nonlinear finite element analysis (FEA) is finally carried out to show the modal frequency and the forced excitation response in the primary motion direction.

Extended Static Modeling and Analysis of Compliant Compound Parallelogram Mechanisms Considering the Initial Internal Axial Force*

2016 ◽  
Vol 8 (4) ◽  
Author(s):  
Guangbo Hao ◽  
Haiyang Li
Keyword(s):  
Axial Force ◽  
Thermal Effects ◽  
Analytical Modeling ◽  
Modeling And Analysis ◽  
Primary Motion ◽  
Axial Forces ◽  
Maximal Stress ◽  
Static Modeling ◽  
Motion Range ◽  
Nonlinear Analytical Model

Extended nonlinear analytical modeling and analysis of compound parallelogram mechanisms are conducted in this paper to consider the effect of the initial internal axial force. The nonlinear analytical model of a compound basic parallelogram mechanism (CBPM) is first derived incorporating the initial internal axial force. The stiffness equations of compound multibeam parallelogram mechanisms (CMPMs) are then followed. The analytical maximal stress under the primary actuation force only is also derived to determine the maximal primary motion (motion range). The influence of initial internal axial forces on the primary motion/stiffness is further quantitatively analyzed by considering different slenderness ratios, which can be employed to consider active displacement preloading control and/or thermal effects. The criterion that the primary stiffness may be considered “constant” is defined and the initial internal axial force driven by a temperature change is also formulated. A physical preloading system to control the initial internal axial force is presented and testing results of the object CBPM are compared with theoretical ones.

Improvements of a Nonlinear Analysis Guideline for the Re-examination of Existing Urban Concrete Structures

2019 ◽  
Author(s):  
Ane de Boer ◽  
Max A. N. Hendriks ◽  
Eva O. L. Lantsoght
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Nonlinear Analysis ◽  
Composite Structures ◽  
Concrete Slab ◽  
Concrete Structures ◽  
Nonlinear Finite Element Analysis ◽  
Nonlinear Finite Element ◽  
Reinforced Concrete Slab ◽  
Element Analysis

<p>The Dutch Ministry of Infrastructure and the Environment is concerned with the safety of existing infrastructure and expected re-analysis of a large number of bridges and viaducts. Nonlinear finite element analysis can provide a tool to assess safety; a more realistic estimation of the existing safety can be obtained.</p><p>Dutch Guidelines, based on scientific research, general consensus among peers, and a long-term experience with nonlinear analysis, allow for a reduction of model and user factors and improve the robustness of nonlinear finite element analyses.</p><p>The 2017 version of the guidelines can be used for the finite element analysis of basic concrete structural elements like beams, girders and slabs, reinforced or prestressed. Existing structures, like box-girder structures, culverts and bridge decks with prestressed girders in composite structures can be analysed.</p><p>The guidelines have been developed with a two-fold purpose. First, to advice analysts on nonlinear finite element analysis of reinforced and pre-stressed concrete structures. Second, to explain the choices made and to educate analysts, related to the responsibility of limiting model uncertainty.</p><p>This paper contains an overview of the latest version of the guideline and its latest validation extensions. Most important impact is the extended operational lifetime of an existing reinforced concrete slab structure.</p>

Nonlinear Analysis of Mechanical Behavior of the Eccentric In-Plane Beam-Wall Joint

2011 ◽  
Vol 243-249 ◽  
pp. 889-892
Author(s):  
Jie Bai
Keyword(s):  
Finite Element Analysis ◽  
Mechanical Behavior ◽  
Nonlinear Analysis ◽  
Parametric Analysis ◽  
Nonlinear Finite Element ◽  
Force Transmission ◽  
Element Analysis ◽  
Bond Slip ◽  
Factors Influencing ◽  
Main Factors

On the basis of previous experimental research, the nonlinear finite element analysis of the eccentric in-plane beam-wall joint is made with nonlinear bond-slip constitutive relation between steel and concrete. The mechanical behavior of the joint is studied in detail, and parametric analysis is carried out for mechanical behavior of the joint. Results of experiment and nonlinear analysis proved that: the important guarantee for mechanical behavior of the eccentric in-plane beam-wall joint is macro resistance capability, which is a precondition of local force transmission of the joint. In addition, the length of beam plunging wall, eccentricity of the joint and the stirrup ratio of beam within wall are the main factors influencing on mechanical behavior of the joint.

Nonlinear Analysis of Concealed Beam in Out-of-Plane Beam-Wall Joint

2012 ◽  
Vol 446-449 ◽  
pp. 498-501
Author(s):  
Jie Bai ◽  
Guo Bai
Keyword(s):  
Nonlinear Analysis ◽  
Constitutive Relations ◽  
Nonlinear Finite Element ◽  
Element Analysis ◽  
Bond Slip ◽  
Factors Influencing ◽  
Out Of Plane ◽  
Transfer Behavior ◽  
Main Factors ◽  
Force Mechanism

On the basis of previous experimental research, the nonlinear finite element analysis of the out-of-plane beam-wall joint is made with nonlinear bond-slip constitutive relations between steel and concrete. The force mechanism of concealed beam in the joint is studied in detail, and parametric analysis is carried out for height of concealed beam. Results of experiment and nonlinear analysis proved that: concealed beam is the important guarantee for mechanical behavior of the out-of-plane beam-wall joint. In addition, the torsional capacity and height of concealed beam are the main factors influencing on moment transfer behavior of the joint.

Investigation into the Effect of the Nut Thread Cutting on the Stress Distribution in a Bolt Using the Finite Element Method

2010 ◽  
Vol 148-149 ◽  
pp. 99-102
Author(s):  
Zhi Dong Duan ◽  
Jun Feng Gao ◽  
Tie Ming Su
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Axial Force ◽  
Load Distribution ◽  
Equivalent Stress ◽  
Hydraulic Press ◽  
Nonlinear Finite Element ◽  
The Finite Element Method ◽  
Thread Cutting ◽  
Axial Forces

In order to abate fatigue fracture at roots of the first or the second hackle thread of bolt used for hydraulic press ,law of stress and load distribution in bolt threads suffered the axial forces were researched by using nonlinear finite element method.It was found that Peak equivalent stress in roots near axial force are abviously greater than these far away axial force when nut threads are in elastic range,but almost are equial to stress in roots far away axial force when 70% nut threads are in plastic region.Nut thread cutting to the fisrt two teeth can improve stress distribution in a bolt ,but these improvement recede quickly as plastic rigions of nut threads extend.

Nonlinear Analysis of Precast Dapped-End Beams

2017 ◽  
Vol 259 ◽  
pp. 184-189
Author(s):  
Michal Hasa ◽  
Miloš Zich
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Nonlinear Analysis ◽  
Material Properties ◽  
Design Procedure ◽  
Nonlinear Finite Element ◽  
Element Analysis ◽  
Design Procedures ◽  
Strut And Tie

This article deals with a nonlinear analysis of the detail of the dapped-end beam, the design of which in practice usually employs the design procedures based on the strut-and-tie method. The article is a follow-up to the contribution released in 2014 which presented the experiment carried out with a view to verify the design procedure and to the study showing the influence of the used amount of vertical and inclined hanger reinforcement on the bearing capacity and behaviour of the detail under load. The experiment also included the tests of material properties performed on the used concrete. Along with the inspection certificates issued for the used reinforcement, these tests served as a basis for the nonlinear finite element analysis by the ATENA software. This article presents and compares the results of the aforementioned analysis and experiment.

scholarly journals On the infinitely-stable rotational mechanism using the off-axis rotation of a bistable translational mechanism

2015 ◽  
Vol 6 (1) ◽  
pp. 75-80 ◽  
Author(s):  
G. Hao ◽  
J. Mullins
Keyword(s):  
Nonlinear Finite Element ◽  
Critical Transition ◽  
Element Analysis ◽  
Primary Motion ◽  
Prior Art ◽  
Transition Points ◽  
Axis Rotation ◽  
Translational Mechanisms ◽  
Rotation Behaviour

Abstract. Different from the prior art concentrating on the primary translation of bistable translational mechanisms this paper investigates the off-axis rotation behaviour of a bistable translational mechanism through displacing the guided primary translation at different positions. Moment-rotation curves obtained using the nonlinear finite element analysis (FEA) for a case study show the multiple stable positions of the rotation under each specific primary motion, suggesting that an infinitely-stable rotational mechanism can be achieved by controlling the primary motion. In addition, several critical transition points have been identified and qualitative testing has been conducted for the case study.

scholarly journals Design and analysis of concrete-filled tubular flange girders under combined loading

2021 ◽  
pp. 136943322110015
Author(s):  
Rana Al-Dujele ◽  
Katherine Ann Cashell
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Failure Modes ◽  
Numerical Study ◽  
Combined Loading ◽  
Torsional Stiffness ◽  
Fe Model ◽  
Combined Effects ◽  
Element Analysis ◽  
Hollow Section

This paper is concerned with the behaviour of concrete-filled tubular flange girders (CFTFGs) under the combination of bending and tensile axial force. CFTFG is a relatively new structural solution comprising a steel beam in which the compression flange plate is replaced with a concrete-filled hollow section to create an efficient and effective load-carrying solution. These members have very high torsional stiffness and lateral torsional buckling strength in comparison with conventional steel I-girders of similar depth, width and steel weight and are there-fore capable of carrying very heavy loads over long spans. Current design codes do not explicitly include guidance for the design of these members, which are asymmetric in nature under the combined effects of tension and bending. The current paper presents a numerical study into the behaviour of CFTFGs under the combined effects of positive bending and axial tension. The study includes different loading combinations and the associated failure modes are identified and discussed. To facilitate this study, a finite element (FE) model is developed using the ABAQUS software which is capable of capturing both the geometric and material nonlinearities of the behaviour. Based on the results of finite element analysis, the moment–axial force interaction relationship is presented and a simplified equation is proposed for the design of CFTFGs under combined bending and tensile axial force.

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