Modal Analysis of Linear Guide Way Junction Surface

2013 ◽  
Vol 380-384 ◽  
pp. 105-108
Author(s):  
Sheng Le Ren ◽  
Tian Yu Cheng ◽  
Ye Dai
Keyword(s):  
Damping Ratio ◽  
Dynamic Performance ◽  
Surface Characteristics ◽  
Test Method ◽  
Joint Surface ◽  
Small Scale ◽  
Static Stiffness ◽  
Element Analysis ◽  
Scale Test ◽  
The Many

Rails is an affordable, fixed, direct the mobile device. Among the many factors that affect performance, the rail surface is a very important factor. This article use test method gets the static stiffness of joint surface and the top five bands of the natural frequency and damping ratio for small linear guides. Test access to the static stiffness will be important in finite element analysis of input parameters. In the course of the study, analysis of dynamic performance of small - scale test guide, Study on Effect of surface characteristics on the structure of the component. By comparing the small guide the results of the analysis and the experimental results to verify the validity and accuracy of the analysis method.

scholarly journals Experimental and Numerical Study for the Shaping Formation of SCST Structures by Cable-tensioning

2013 ◽  
Vol 7 (1) ◽  
pp. 77-83
Author(s):  
J.W. Kim ◽  
J. H. Doh ◽  
S. Fragomeni
Keyword(s):  
Numerical Study ◽  
Geometric Model ◽  
Small Scale ◽  
Element Analysis ◽  
Construction Technique ◽  
Construction Methods ◽  
Space Truss ◽  
Test Models ◽  
Scale Test ◽  
Joint Behaviour

This paper discusses the behaviour characteristics of the shaping formation of Single-Chorded Space Truss (SCST) structures by means of cable-tensioning of bottom chords. The innovative technique is fast and economical and issued in many types of space structures. The small-scale test models presented herein consist of uniform pyramids with multi-directional ball type joints which are erected into their final shape by cable-tensioning. Since the joint behaviour is very significant in studying the shaping of SCST structures, basic tests for beam and pyramidal units were performed. The feasibility of the proposed cable-tensioning technique and the reliability of the established geometric model were confirmed by finite element analysis. The proposed cable-tensioning technique indicates that the behaviour characteristic of joints is very important in the shaping formation of SCST structures. More specifically in situations where heavy cranes are inaccessible, the cable-tensioning construction technique has proven to be an easy and reasonable method compared to conventional construction methods that typically include heavy cranes and scaffolding.

scholarly journals Infiltration Capacity of Rain Gardens Using Full-Scale Test Method: Effect of Infiltration System on Groundwater Levels in Bergen, Norway

Land ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 520
Author(s):  
Guri Venvik ◽  
Floris Boogaard
Keyword(s):  
Full Scale ◽  
Cold Climate ◽  
Test Method ◽  
Small Scale ◽  
Delayed Response ◽  
Rain Gardens ◽  
Infiltration Capacity ◽  
Runoff Water ◽  
Infiltration Test ◽  
Scale Test

The rain gardens at Bryggen in Bergen, Western Norway, is designed to collect, retain, and infiltrate surface rainfall runoff water, recharge the groundwater, and replenish soil moisture. The hydraulic infiltration capacity of the Sustainable Drainage System (SuDS), here rain gardens, has been tested with small-scale and full-scale infiltration tests. Results show that infiltration capacity meets the requirement and is more than sufficient for infiltration in a cold climate. The results from small-scale test, 245–404 mm/h, shows lower infiltration rates than the full-scale infiltration test, with 510–1600 mm/h. As predicted, an immediate response of the full-scale infiltration test is shown on the groundwater monitoring in the wells located closest to the infiltration point (<30 m), with a ca. 2 days delayed response in the wells further away (75–100 m). Results show that there is sufficient capacity for a larger drainage area to be connected to the infiltration systems. This study contributes to the understanding of the dynamics of infiltration systems such as how a rain garden interacts with local, urban water cycle, both in the hydrological and hydrogeological aspects. The results from this study show that infiltration systems help to protect and preserve the organic rich cultural layers below, as well as help with testing and evaluating of the efficiency, i.e., SuDS may have multiple functions, not only storm water retention. The functionality is tested with water volumes of 40 m3 (600 L/min for 2 h and 10 min), comparable to a flash flood, which give an evaluation of the infiltration capacity of the system.

scholarly journals Eliminating Underconstraint in Double Parallelogram Flexure Mechanisms

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Robert M. Panas ◽  
Jonathan B. Hopkins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Measurement ◽  
Degrees Of Freedom ◽  
Dynamic Performance ◽  
Average Error ◽  
Static Stiffness ◽  
Element Analysis ◽  
Linkage Design ◽  
Analytical Expressions

We present an improved flexure linkage design for removing underconstraint in a double parallelogram (DP) linear flexural mechanism. This new linkage alleviates many of the problems associated with current linkage design solutions such as static and dynamic performance losses and increased footprint. The improvements of the new linkage design will enable wider adoption of underconstraint eliminating (UE) linkages, especially in the design of linear flexural bearings. Comparisons are provided between the new linkage design and existing UE designs over a range of features including footprint, dynamics, and kinematics. A nested linkage design is shown through finite element analysis (FEA) and experimental measurement to work as predicted in selectively eliminating the underconstrained degrees-of-freedom (DOF) in DP linear flexure bearings. The improved bearing shows an 11 × gain in the resonance frequency and 134× gain in static stiffness of the underconstrained DOF, as designed. Analytical expressions are presented for designers to calculate the linear performance of the nested UE linkage (average error < 5%). The concept presented in this paper is extended to an analogous double-nested rotary flexure design.

Experimental Study on the Performance of the Laminated Steel Isolators

2013 ◽  
Vol 423-426 ◽  
pp. 1603-1607
Author(s):  
Yao Guo Xie ◽  
Ping He ◽  
Xian Qiang Qu ◽  
Hong Bin Cui
Keyword(s):  
Experimental Study ◽  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Performance Testing ◽  
Stiffness Ratio ◽  
Static Stiffness ◽  
Comparison Of The Results

Through the analysis and comparison of the results of static and dynamic performance testing of a series of laminated steel pieces isolators used in the vibration isolation of warships, in the number and thickness of laminated steel pieces of the same circumstances, laminated steel arc and preload of test samples had a certain impact on the values ​​of static stiffness, dynamic stiffness, damping ratio as well as dynamic and static stiffness ratio.

scholarly journals Mechanical Modal Phenomena of a Ganged Heliostat

2017 ◽  
Author(s):  
Kenneth M. Armijo ◽  
Jesus D. Ortega ◽  
Adam Moya ◽  
Joshua Christian ◽  
Gregory Peacock ◽  
...  
Keyword(s):  
Solar Collector ◽  
Simulation Software ◽  
Small Scale ◽  
Element Analysis ◽  
Impact Performance ◽  
Modal Test ◽  
Fea Model ◽  
Cost Reductions ◽  
The Many ◽  
Good Agreement

Ganged-heliostats have the potential for large cost reductions with enhanced solar collector field optimization. Unlike typical heliostats that require dual axis tracking actuators and a base or foundation, ganged-heliostats can share actuation and a support structure. This membership greatly reduces system infrastructure and installation costs. However, concentrating solar power (CSP) heliostats are subjected to wind-induced loads, vibration, and gravity-induced deformations. These effects could impact performance and reliability of these structures, where despite the many advantages for the utility of ganged heliostats, modal limitations exist from wind perturbations. In this investigation, an introductory multiphysics finite element analysis (FEA) model was developed using SolidWorks Simulation software to validate experimental measurements of a novel small-scale ganged heliostat system, parametrically under varying azimuth rotations, facet pitch levels, and cable tension levels. The ganged heliostat design featured a number of mirrors resting on two guide wires which were tensioned and rotated to align with any given target. Experimentally, several standard modal tests were conducted on the ganged heliostat, which was designed to operate under a number of orientations, where for this investigation two scenarios were selected to be representative of an operational heliostat. The heliostat was oriented at a 0° (face up) and 45° orientations for the modal test configurations. The modal tests were computationally validated in good agreement with the experiments to within 2.8% and 6.3% error for 0° and 45° orientations respectively.

An experimental investigation of hydrodynamic damping due to vertical baffle arrangements in a rectangular tank

2007 ◽  
Vol 221 (3) ◽  
pp. 115-123 ◽  
Author(s):  
M F Younes ◽  
Y K Younes ◽  
M El-Madah ◽  
I M Ibrahim ◽  
E H El-Dannanh
Keyword(s):  
Damping Ratio ◽  
Small Scale ◽  
Test Rig ◽  
Transient Responses ◽  
Hydrodynamic Damping ◽  
Liquid Slosh ◽  
Liquid Free Surface ◽  
Rectangular Tank ◽  
Scale Test ◽  
Vertical Baffle

The present work is concerned with an experimental study of the hydrodynamic damping provided by using vertical baffles in partially filled rectangular tanks. The damping ratio is evaluated for different vertical baffle dimensions, shapes, numbers, and arrangements. A small-scale test rig consisting of a partially filled rectangular tank with a pendulum suspension is designed and constructed to measure the transient responses of the system. The baffles are fitted to attenuate the lateral motion of the liquid slosh. Lower mounted and upper mounted vertical baffles of different heights and numbers are tested. Lower mounted vertical baffles with holes of different sizes and numbers are considered. Finally, the effect of a combination between upper, lower, and holed vertical baffles on the system damping is investigated. The results show that the size and location of the vertical baffles significantly influence the hydrodynamic damping. In general, the damping ratio increases as the tip of the lower mounted baffle plate is close to the liquid free surface and the location of the plate is close to the centre of the tank. Increasing the baffle numbers increases the damping ratio. The upper mounted vertical baffles are more suitable for a chargeable tank. The twin side upper mounted baffles and centre-holed lower mounted baffle arrangements give a maximum damping ratio.

Analysis on the Influencing Factors of Dynamic Characteristics for the Linear Motion Station of DCG

2013 ◽  
Vol 437 ◽  
pp. 194-197
Author(s):  
Xiao Peng Li ◽  
Xing Ju ◽  
Guang Hui Zhao ◽  
Ya Min Liang ◽  
Hao Tian Yang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Dynamic Performance ◽  
Cnc Machine Tools ◽  
Joint Surface ◽  
Design Parameters ◽  
Machining Accuracy ◽  
Cnc Machine ◽  
Element Analysis ◽  
Feed Drive

Dynamic characteristics of the system have been given more and more attention so as to improve the retention and reliability of machining accuracy. Research has shown that dynamic performance of the feed drive mechanism has significant impact on the processing quality and efficiency of CNC. This paper mainly focuses on the DCG which realizes its motion on the basis of a pair of lead screw. The dynamic performance of the DCG was analyzed by the method of finite element analysis. DCG structure and the key design parameters of the rail joint surface have been studied to find out the influence on its dynamic characteristics. These researches provided a basis for the realization of the CNC feed motion of high-speed and high-precision. Besides, it is also possible to improve the overall performance of CNC machine tools.

The Research of the Assembly Precision of CNC Machine Tools Considering the Joint Surface Characteristics

2013 ◽  
Vol 397-400 ◽  
pp. 198-201
Author(s):  
Wan Yu Li ◽  
Cong Lu ◽  
Zhuo Yang
Keyword(s):  
Machine Tools ◽  
Surface Deformation ◽  
Surface Characteristics ◽  
Cnc Machine Tools ◽  
Joint Surface ◽  
Surface Model ◽  
Assembly Sequence ◽  
Cnc Machine ◽  
Element Analysis ◽  
Assembly Precision

In order to evaluate the assembly precision of the CNC machine tools influenced by the joint surface characteristics effectively, a method is proposed in this paper. Finite element analysis is used to obtain joint surface deformation data, and then a second-order response surface model is established as a surrogate model to express the function of joint surface static characteristics and deformation. The error propagation in assembly sequence is obtained, so that the assembly precision of CNC machine tools can be evaluated effectively.

Dynamic Properties of Long-Span Steel-Concrete Composite Bridges with External Tendons

2013 ◽  
Vol 831 ◽  
pp. 359-363
Author(s):  
Wei An Wang ◽  
Qiao Li ◽  
Can Hui Zhao ◽  
Wei Lin Zhuang
Keyword(s):  
Dynamic Properties ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Dynamic Interactions ◽  
Element Analysis ◽  
Structural Dynamic ◽  
Equivalent Damping ◽  
Shear Connectors ◽  
External Tendons ◽  
Composite Bridges

The dynamic performance of large-span steel-concrete composite bridges with external tendons is investigated by deriving the formula of equivalent damping ratios of composite bridges, and by considering the influence of shear connectors stiffness of composite girders, external tendons, and pile-soil dynamic interactions on the dynamic properties of steel-concrete composite bridge. Finite element analysis indicates that the equivalent damping ratio has a significant influence on the dynamic response and damping coefficient adjusted must be conducted in structural dynamic analysis.

SMALL-SCALE TEST METHOD FOR RAILWAY DYNAMICS

1986 ◽  
Vol 15 (sup1) ◽  
pp. 197-207 ◽  
Author(s):  
Coralie Heliot
Keyword(s):  
Test Method ◽  
Small Scale ◽  
Railway Dynamics ◽  
Scale Test
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