Downwards force-displacement response of buried pipelines during dip-slip faulting in sandy soil

Author(s):  
Hamid Tohidifar ◽  
Mohammad Kazem Jafari ◽  
Mojtaba Moosavi

In the numerical analysis of underground pipelines against dip-slip faulting, it is common practice to model the problem as a beam surrounded by soil-equivalent nonlinear springs. Previous studies have recognised the importance of the Vertical Bearing Soil Springs (VBSS) in the modelling of pipe-fault interaction. Nevertheless, prior studies on VBSS are limited. This study presents an analytical framework for determining a hyperbolic P-y curve for VBSS in dry sand. This hyperbolic criterion was established based on the Ultimate Bearing Resistance (UBR) of pipe and the elastic subgrade modulus of the soil. Different mechanisms such as flow, arching, bearing, and friction, and various parameters like soil compressibility, pipe-soil relative stiffness, and soil elastic properties have been used in the determination of these two parameters. The P-y curves were verified and calibrated with experimental data. More reliable curves have been obtained compared to the existing methods. A numerical study was also performed to compare the current study with a pipeline seismic design Guideline. The results of the current study method were in good agreement with sample experimental data compared to the seismic Guideline.

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Vivienne Bürgin ◽  
A. U. Daniels ◽  
Silvia Francioli ◽  
Jörg Schulenburg ◽  
Dieter Wirz

One promising treatment of localized osteochondral defects in the knee joint may be the implantation of in vitro tissue-engineered osteochondral constructs. A crucial aspect of this kind of osteochondral construct is the bonding between the bone-scaffold and scaffold-based chondral layer. Here, a 90° peel off test is proposed as an appropriate method to measure the integration of cartilage to bone in osteochondral constructs for different primary methods of bonding the cartilage scaffold to the bone scaffold, with and without seeded chondroblasts. The method was developed and then tested on tissue-engineered constructs. The force/displacement data obtained allow determination of both the maximum force and the total energy required to separate the two layers. The tests showed good reproducibility and good discrimination between measurements as a function of seeding times. Average maximum peel-off forces varied between 10 mN for fibrin glue only to 575 mN for constructs with cells after four weeks of incubation. Linear regression of the area under the curve (AUC) as a function of maximum force shows a high correlation between the two parameters with R2 = 0.97. The main limitation of the test is that the data provide only a modest ability to decide how uniform the bond is over the area between the two layers.


1968 ◽  
Vol 12 ◽  
Author(s):  
R. Goossens

A precise method for the determination of the increment of the  basal area using the PressIer bore. Refering to  previous research showing that the basal area of the corsica pine could be  characterized by an ellips, we present in this paper a precise method for the  determination of the increment of the basal area. In this method we determine  the direction of the maximum diameter, we measure this diameter and we take a  core in one of the points of tangency of the caliper with the measured tree.  The determination of the diameter perpendicular to the maximum diameter  finishes the work wich is to be done in the forest. From the classical  measurements effectuated on the core and from the measured diameters we can  then determine the form (V) and the excentricity (e). Substituting these two  parameters in the formula 2 or 2', we can also calculate the error of a  radius measured on the core with respect to the representative radius, This  error with them allow us to correct the measured value of the minimum or the  maximum radius and we will be able to do a precise determination of the  increment.


1992 ◽  
Vol 57 (9) ◽  
pp. 1905-1914
Author(s):  
Miroslav Bleha ◽  
Věra Šumberová

The equilibrium sorption of uni-univalent electrolytes (NaCl, KCl) in heterogeneous cation exchange membranes with various contents of the ion exchange component and in ion exchange membranes Ralex was investigated. Using experimental data which express the concentration dependence of equilibrium sorption, validity of the Donnan relation for the systems under investigation was tested and values of the Glueckauf inhomogeneity factor for Ralex membranes were determined. Determination of the equilibrium sorption allows the effect of the total content of internal water and of the ion-exchange capacity on the distribution coefficients of the electrolyte to be determined.


Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.


2021 ◽  
Vol 18 (1) ◽  
pp. 25-52
Author(s):  
Sui He

Abstract Cognitive metaphor theory provides a systematic framework to better understand the working mechanism of metaphor. Its recent development further allows translation researchers to have a clearer insight into the movement of metaphor across languages and culture. Building on an empirical study, this paper examines the complementary relationship between two prominent cognitive metaphor theories – Conceptual Metaphor Theory (CMT) and Conceptual Blending Theory (CBT), and discusses the practical contribution that this relationship could make to the existing research on metaphor translation. To construct a comparable basis for CMT and CBT, two parameters are adopted for data analysis, which is proven useful to serve the purpose. The two chosen parameters are: projection and provenance, denoting the content and the type of metaphor respectively. Metaphorical expressions analyzed in this paper are sourced from cosmology-themed articles published in Scientific American in 2017 and their Simplified Chinese translations published in Huanqiukexue. Findings show that delineated by the two parameters, CMT and CBT indeed share a complementary relationship owing to their different focuses and organizing mechanisms. Furthermore, the collaboration between CMT and CBT offers a well-rounded analytical framework for translation studies. In turn, the correlation between metaphor parameters and translation solutions provides detailed clues for studying metaphor across culture. Finally, the reflection of this dual-model parametric approach regarding its pros and cons is also shown to shed light on future research.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110094
Author(s):  
Ibrahim Elnasri ◽  
Han Zhao

In this study, we numerically investigate the impact perforation of sandwich panels made of 0.8 mm 2024-T3 aluminum alloy skin sheets and graded polymeric hollow sphere cores with four different gradient profiles. A suitable numerical model was conducted using the LS-DYNA code, calibrated with an inverse perforation test, instrumented with a Hopkinson bar, and validated using experimental data from the literature. Moreover, the effects of quasi-static loading, landing rates, and boundary conditions on the perforation resistance of the studied graded core sandwich panels were discussed. The simulation results showed that the piercing force–displacement response of the graded core sandwich panels is affected by the core density gradient profiles. Besides, the energy absorption capability can be effectively enhanced by modifying the arrangement of the core layers with unclumping boundary conditions in the graded core sandwich panel, which is rather too hard to achieve with clumping boundary conditions.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1226
Author(s):  
Pakorn Ditthakit ◽  
Sirimon Pinthong ◽  
Nureehan Salaeh ◽  
Fadilah Binnui ◽  
Laksanara Khwanchum ◽  
...  

Accurate monthly runoff estimation is crucial in water resources management, planning, and development, preventing and reducing water-related problems, such as flooding and droughts. This article evaluates the monthly hydrological rainfall-runoff model’s performance, the GR2M model, in Thailand’s southern basins. The GR2M model requires only two parameters: production store (X1) and groundwater exchange rate (X2). Moreover, no prior research has been reported on its application in this region. The 37 runoff stations, which are located in three sub-watersheds of Thailand’s southern region, namely; Thale Sap Songkhla, Peninsular-East Coast, and Peninsular-West Coast, were selected as study cases. The available monthly hydrological data of runoff, rainfall, air temperature from the Royal Irrigation Department (RID) and the Thai Meteorological Department (TMD) were collected and analyzed. The Thornthwaite method was utilized for the determination of evapotranspiration. The model’s performance was conducted using three statistical indices: Nash–Sutcliffe Efficiency (NSE), Correlation Coefficient (r), and Overall Index (OI). The model’s calibration results for 37 runoff stations gave the average NSE, r, and OI of 0.657, 0.825, and 0.757, respectively. Moreover, the NSE, r, and OI values for the model’s verification were 0.472, 0.750, and 0.639, respectively. Hence, the GR2M model was qualified and reliable to apply for determining monthly runoff variation in this region. The spatial distribution of production store (X1) and groundwater exchange rate (X2) values was conducted using the IDW method. It was susceptible to the X1, and X2 values of approximately more than 0.90, gave the higher model’s performance.


1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.


1989 ◽  
Vol 209 ◽  
pp. 285-308 ◽  
Author(s):  
R. J. Bodonyi ◽  
W. J. C. Welch ◽  
P. W. Duck ◽  
M. Tadjfar

A numerical study of the generation of Tollmien-Schlichting (T–S) waves due to the interaction between a small free-stream disturbance and a small localized variation of the surface geometry has been carried out using both finite–difference and spectral methods. The nonlinear steady flow is of the viscous–inviscid interactive type while the unsteady disturbed flow is assumed to be governed by the Navier–Stokes equations linearized about this flow. Numerical solutions illustrate the growth or decay of the T–S waves generated by the interaction between the free-stream disturbance and the surface distortion, depending on the value of the scaled Strouhal number. An important result of this receptivity problem is the numerical determination of the amplitude of the T–S waves.


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