Theory Analysis of Full-Scale Segment Model of Huaian Cable-Stayed Bridge Pylon

2011 ◽  
Vol 71-78 ◽  
pp. 4614-4618
Author(s):  
Hong Yuan Tang ◽  
Zhe Lin Fan
Keyword(s):  
Model Test ◽  
Mechanical Performance ◽  
Theoretical Method ◽  
Full Scale ◽  
Stress Distributions ◽  
Segment Model ◽  
Theoretical Support ◽  
Test Study ◽  
Cable Force ◽  
The Difference

The difference of the mechanical performance between the whole bridge pylon and the segment model are analyzed in theoretical method to provide theoretical support for the full-scale segmental model test study. Firstly, choose the most representative full-scale segment in anchorage zone of bridge pylon. Secondly, select the whole model composed of several segments. Finally, analysis the stress distributions in two models under the working load and the cracking load. In the coordinate segment position, stress distribution under design cable force in whole model and full scale segment model is almost the same. It indicates that the working performance of the anchorage zone in the bridge pylon can be studied through the full-scale segment model test.

Laboratory Model Test Study of Tunnel Anchor

2014 ◽  
Vol 1065-1069 ◽  
pp. 333-336
Author(s):  
Bing Shen ◽  
Sai Qiong Long ◽  
Jun Chen ◽  
Yong Bing Li
Keyword(s):  
Model Test ◽  
Shear Failure ◽  
Failure Surface ◽  
Tensile Failure ◽  
Laboratory Model ◽  
Pull Out ◽  
Test Study ◽  
Cable Force ◽  
Anchor Design ◽  
Laboratory Model Test

A laboratory model test of tunnel anchor was conducted to investigate its pullout mechanism and bearing capacity. Surface and rock deformation, strain and stress were measured during the entire model test process. The results show that: under pull out load, tensile failure first occurs in top surface rock near the anchor, then shear failure occurs in anchor-rock interface and rock around the anchor. The failure surface is inverted cone from the anchor bottom. Under 50 times design cable force tunnel rock is in elastic stage, suggesting that current tunnel anchor design is quite conservative and can be further optimized.

scholarly journals THE RESISTANCE ASPECT OF FISHING BOAT SKIPJACK POLE AND LINE

2021 ◽  
Vol 4 ◽  
pp. 1-7
Author(s):  
Wolter R Hetharia ◽  
Eliza R De Fretes ◽  
Reico H Siahainenia
Keyword(s):  
Model Test ◽  
Ship Design ◽  
Full Scale ◽  
Suitable Method ◽  
Design Phase ◽  
Towing Tank ◽  
Model Scale ◽  
Fishing Boat ◽  
Fishing Vessels ◽  
The Difference

The operation of fishing vessels skipjack pole and line contributes in catching tuna and skipjack fishes particularly in Indonesian waters. A previous study conducted by the authors found that there was no suitable method provided for the resistance computation atearly ship design phase. Besides, there was aninitial trim existed on the vessel during the operation which contributes for the resistance. The purpose of the study is to find the difference of resistance between the model test and the existing methods. The study was executed also to find the effect of initial trim of the vessel. The study began with collecting the database of a parent ship then to develop and transform into a model-scale for testing purpose in the towing tank. The results of model test were converted to the full-scale vessel. The resistance of full-scale vessel was computed based on the Holtrop and Guldhammer methods. The result of full-of resistance obtained from the model test and the methods were collected, evaluated and compared. The results showed the difference of the resistance for all methods. The result of model test is greater 21 % than that of Holtrop method at the service speed of 10 knots. Meanwhile, the result of model test is lower 14 % than that of Gulhammer method at the same speed. In addition, at the speed of 10 knots the initial trim of 0.5O increase 5 % ofthe resistance, the initial trim of 1O increase 10 % of resistance and the initial trim of 2O increase 16 % of resistance compared to the vesselwithout initial trim. In conclusion, the existing resistance methods are not suitable to be applied for skipjack pole and line fishing vessels. In addition, the initial trim contributes to increase the resistance and should be avoided during the vessel operation.

scholarly journals Model Test Study on the Influence of Ground Surcharges on the Deformation of Shield Tunnels

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1565
Author(s):  
Gang Wei ◽  
Shuming Zhang ◽  
Pengfei Xiang
Keyword(s):  
Model Test ◽  
Three Dimensional ◽  
Theoretical Method ◽  
Shield Tunnel ◽  
Burial Depth ◽  
Scaled Model ◽  
Test Study ◽  
Dimensional Finite Element ◽  
Calculation Results ◽  
Three Dimensional Finite Element

Aiming at studying the harm caused by sudden ground loadings on existing shield tunnels, a indoor scaled model test with a geometric similarity ratio of 1:15.5 was adopted. Considering the influencing factors such as ground loading, burial depth of the shield tunnel, loading position and soil properties, tunnel convergence deformation, tunnel settlement and deep settlement of soil caused by sudden ground loadings are studied. A three-dimensional finite element simulation is carried out using the Midas software, and deep settlement of soil is calculated by a theoretical method. The purpose of this model test is to further understand the influence of ground surcharges on shield tunnel deformation. The results show that the greater the ground surcharge, the greater the settlement and vertical convergence deformation of the shield tunnel; The further away from the ground surcharge, the smaller the settlement, vertical convergence deformation and lateral convergence deformation of the tunnel. When the pile load size is constant, the greater the burial depth of the tunnel, the smaller the vertical convergence deformation and settlement of the tunnel; the maximum value of deep settlement of the soil always remains at the closest point to the ground surcharge; compared with the use of dry sand, the vertical convergence deformation and settlement of the tunnel are significantly reduced when using wet sand. Both the theoretical calculation results and the numerical simulation results are in good agreement with the indoor model test results.

Determining Side-by-Side Current Loads Using CFD and Model Tests

2016 ◽  
Author(s):  
Arjen Koop
Keyword(s):  
Reynolds Number ◽  
Model Test ◽  
Full Scale ◽  
Test Results ◽  
Model Scale ◽  
Moment Coefficient ◽  
The Difference ◽  
The Moment ◽  
Good Agreement ◽  
Shielding Effects

When two vessels are positioned close to each other in a current, significant shielding or interaction effects can be observed. In this paper the current loads are determined for a LNG carrier alone, a Shuttle tanker alone and both vessels in side-by-side configuration. The current loads are determined by means of tow tests in a water basin at scale 1:60 and by CFD calculations at model-scale and full-scale Reynolds number. The objective of the measurements was to obtain reference data including shielding effects. CFD calculations at model-scale Reynolds number are carried out and compared with the model test results to determine the capability of CFD to predict the side-by-side current load coefficients. Furthermore, CFD calculations at full-scale Reynolds number are performed to determine the scale effects on current loads. We estimate that the experimental uncertainty ranges between 3% and 5% for the force coefficients CY and CMZ and between 3% and 10% for CX. Based on a grid sensitivity study the numerical sensitivity is estimated to be below 5%. Considering the uncertainties mentioned above, we assume that a good agreement between experiments and CFD calculations is obtained when the difference is within 10%. The best agreement between the model test results and the CFD results for model-scale Reynolds number is obtained for the CY coefficient with differences around 5%. For the CX coefficient the difference can be larger as this coefficient is mainly dominated by the friction component. In the model tests this force is small and therefore difficult to measure. In the CFD calculations the turbulence model used may not be suitable to capture transition from laminar to turbulent flow. A good agreement (around 5% difference) is obtained for the moment coefficient for headings without shielding effects. With shielding effects larger differences can be obtained as for these headings a slight deviation in the wake behind the upstream vessel may result in a large difference for the moment coefficient. Comparing the CFD results at full-scale Reynolds number with the CFD results at model-scale Reynolds number significant differences are found for friction dominated forces. For the CX coefficient a reduction up to 50% can be observed at full-scale Reynolds number. The differences for pressure dominated forces are smaller. For the CY coefficient 5–10% lower values are obtained at full-scale Reynolds number. The moment coefficient CMZ is also dominated by the pressure force, but up to 30% lower values are found at full-scale Reynolds number. The shielding effects appear to be slightly smaller at full-scale Reynolds number as the wake from the upstream vessel is slightly smaller in size resulting in larger forces on the downstream vessel.

Full-Scale Segment Model Test and Stress Analysis of Abnormally Shaped Anchorage Zone of Cable-Stayed Bridge Pylon

2012 ◽  
Vol 446-449 ◽  
pp. 1148-1152 ◽  
Author(s):  
Yue Li ◽  
Qin Feng Cai
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Model Test ◽  
Resistance Coefficient ◽  
Full Scale ◽  
Element Analysis ◽  
Segment Model ◽  
Cable Stayed Bridge ◽  
The Finite Element Analysis ◽  
Contrast Analysis

The anchorage zone of pylon is the key part of the cable-stayed bridge, and it is also the difficult and important part in designing and construction of cable-stayed bridge. Especially for an abnormally shaped anchorage zone, it is hard to analyze the actual stress distribution on the bridge pylon by a simple mechanical method. The full scale segment model test of the abnormally anchorage zone of Maling River cable-stayed bridge pylon was described. In the test, the cracks, stress and deformation were observed and analyzed. Further more, the finite element analysis for the segment model was carried out. Through the contrast analysis between the model test and the finite element analysis, some important conclusions are drawn such as the model test and the finite element analysis have a good agreement, “the joints outside” and “the polyline inside” are the easy cracking zones, the cracking resistance coefficient of the model is no less than 1.3 and the destroy safety coefficient is no less than 1.6, which can provide important theoretical basis for the design and construction.

Model Test Study on a Large-Section Cable Tunnel

2013 ◽  
Vol 353-356 ◽  
pp. 1411-1416
Author(s):  
Jun Sheng Chen ◽  
Shu Zhuo Liu ◽  
Ren Guo Gu ◽  
Ying Guang Fang ◽  
Hai Hong Mo
Keyword(s):  
Model Test ◽  
Full Scale ◽  
Scale Model ◽  
Shield Tunnel ◽  
Large Section ◽  
Horizontal Beam ◽  
Test Study ◽  
Safety And Reliability ◽  
Cable Laying ◽  
Design Loads

The profile layout rationality and internal stress structure of a large-section cable tunnel and a cable-laying scheme at splicing locations were studied through full-scale model test. The full scale shield tunnel which the diameter was 6m was built on the ground. The model tests test the displacement of cable bearers, the coupling area between horizontal beam and steel ring, the coupling area between horizontal beam and steel pillar, edge beam and center beam under design loads, and the safety and reliability of an arc steel framing system that supports the cable load inside the cable tunnel during the operation stage were demonstrated. The cable-laying schemes for the cross section and straight-through-type and T-type couplings of a large-section cable tunnel were optimized through experiment on actually laid-out cables. For the section layout of a large-section cable tunnel, it is believed that the double-deck scheme prevails over the single-deck scheme, and such a cable-splicing scheme can meet the cable-laying requirement.

A Modification of the Payne-Jones Method of Identifying Abnormal Differences in WISC-R Performance and Verbal IQ's

1996 ◽  
Vol 12 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Louis M. Hsu
Keyword(s):  
Full Scale ◽  
True Score ◽  
Verbal Iq ◽  
Score Difference ◽  
The Difference ◽  
And Performance

The difference (D) between a person's Verbal IQ (VIQ) and Performance IQ (PIQ) has for some time been considered clinically meaningful ( Kaufman, 1976 , 1979 ; Matarazzo, 1990 , 1991 ; Matarazzo & Herman, 1985 ; Sattler, 1982 ; Wechsler, 1984 ). Particularly useful is information about the degree to which a difference (D) between scores is “abnormal” (i.e., deviant in a standardization group) as opposed to simply “reliable” (i.e., indicative of a true score difference) ( Mittenberg, Thompson, & Schwartz, 1991 ; Silverstein, 1981 ; Payne & Jones, 1957 ). Payne and Jones (1957) proposed a formula to identify “abnormal” differences, which has been used extensively in the literature, and which has generally yielded good approximations to empirically determined “abnormal” differences ( Silverstein, 1985 ; Matarazzo & Herman, 1985 ). However applications of this formula have not taken into account the dependence (demonstrated by Kaufman, 1976 , 1979 , and Matarazzo & Herman, 1985 ) of Ds on Full Scale IQs (FSIQs). This has led to overestimation of “abnormality” of Ds of high FSIQ children, and underestimation of “abnormality” of Ds of low FSIQ children. This article presents a formula for identification of abnormal WISC-R Ds, which overcomes these problems, by explicitly taking into account the dependence of Ds on FSIQs.

A Model Test Study on the Effect of the Stern Interceptor for the Reduction of the Resistance and Trim Angle for Wave-piercing Hulls

2015 ◽  
Vol 52 (6) ◽  
pp. 485-493 ◽  
Author(s):  
Dae Hyuk Kim ◽  
Inn-Duk Seo ◽  
Key-Pyo Rhee ◽  
Nakwan Kim ◽  
Jin-Hyung Ahn
Keyword(s):  
Model Test ◽  
Test Study
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