Relationships between lateral and rotational load transfer stiffnesses and soil modulus for the elastic response of monopiles

2021 ◽  
Vol 137 ◽  
pp. 104256
Author(s):  
Xiao Wan ◽  
James P. Doherty ◽  
Mark F. Randolph
Keyword(s):  
Load Transfer ◽  
Elastic Response ◽  
Soil Modulus ◽  
Rotational Load

Three-Dimensional Analyses of Single Rivet-Row Lap Joints — Part I: Elastic Response

1999 ◽  
Author(s):  
K. Iyer ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Stress Concentration ◽  
Load Transfer ◽  
Three Dimensional ◽  
Lap Joints ◽  
Elastic Response ◽  
Lap Joint ◽  
Out Of Plane ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Contact Pressures

Abstract Three-dimensional finite element analyses (FEA) of an elastic, single rivet-row, aluminum alloy lap joint are presented. The effects of rivet geometry (countersinking), rivet material and interfacial friction coefficient are examined. Interference and lateral clamping are not treated. Panels loaded in tension with vacant, tapered holes are also examined. Load transfer through the joint, the joint compliance, rivet-tilt, the local slips at rivet-panel and panel-panel interfaces, contact pressures and local stresses are evaluated. Relations between these features and the contact and bending driven stress concentration are clarified. The work shows that the stress concentration factor, rivet-panel slips, peak stresses, contact pressures and rivet deformation are all related, and increase with the severity of the countersink. Panel bending, rivet tilt and countersinking introduce large, out-of-plane stress gradients and shift the peak stresses to the interior surface of the countersunk panel. The results demonstrate the importance of out-of-plane distortions in accounting for the behavior of the riveted lap joints. Three opportunities are identified for improving lap joint performance without increasing the weight.

Numerical Analysis of Mechanical Interaction of Pipe-in-Pipe Flowline

2017 ◽  
Author(s):  
M. T. Akolawole ◽  
Yongchang Pu
Keyword(s):  
Numerical Analysis ◽  
Load Transfer ◽  
Structural Response ◽  
Material Model ◽  
Polyamide 6 ◽  
Elastic Response ◽  
Mechanical Interaction ◽  
High Production Rate ◽  
The Impact ◽  
Outer Pipe

Pipe-in-pipe (PIP) flowline is a unique solution for long subsea tie-backs in deepwater and ultra-deepwater fields. This is because of its optimum thermal performance over wet insulation. However, pipelines are subjected to the highest loading condition during installation. Significant limitation imposed on existing installation vessel in deepwater, is peculiar to S-lay installation method. Contrary to the level of stress experienced with the S-lay installation method at specific locations such as overbend and sagbend region, this method is still widely utilized because of its high production rate. These regions are dominated by bending curvatures which are defined by different load conditions. Due to the composition of PIP system, it is important to understand the structural response of the flowline, the mechanical interaction occurring between various components and the amount of load transfer at this location. Although, the mechanical interaction within the PIP system are case specific. However, it has been observed that prior to case study analysis; simple pipe models are being developed to assess the mechanical interaction of this system. This paper addresses the impact of the centralizer material on the structural response and load transfer between the outer pipe and inner pipe. The numerical analysis was carried out using Ansys software and was based on Euler Bernoulli bending theory. The centralizer was clamped on to the inner pipe with the clearance between the centralizer and the outer pipe included in the model. The core of the analysis, was modeling the visco-elastic response of nylon rings (Polyamide 6), from which centralizers are made. The centralizer was spaced based on S-lay or J-lay installation criteria against heat sink. The results demonstrated the relationship between spacing of the centralizer and areas of first contact, amount of force transferred through the centralizer material, non-linearity introduced by contact formulation, alongside the time and temperature dependent behavior of visco-elastic material. The result correlated accurately with the bending principle. Different material model was assessed to determine accuracy of results obtained, in the absence of experimental test data to model visco-elastic response. In addition, the bending curvature was used to predict the mechanical interaction in installation and operation analysis, where limitations of explicitly modeling centralizers exist.

Influence of Cold Work in the Elastic Modulus of the Ti-16.2Hf-24.8Nb-1Zr Alloy Characterized by Instrumented Nanoindentation

2009 ◽  
Vol 423 ◽  
pp. 113-118 ◽  
Author(s):  
Marta González ◽  
J. Peña ◽  
Jose Maria Manero ◽  
F.J. Gil
Keyword(s):  
Elastic Modulus ◽  
Shape Memory ◽  
Load Transfer ◽  
Cold Work ◽  
Elastic Response ◽  
Vacuum Arc ◽  
Damping Capacity ◽  
Heat Treated ◽  
Low Elastic Modulus ◽  
Cold Worked

Nowadays, β type Ti-based alloys have been developed for load transfer clinical applications due to their superelasticity, shape memory effect, low elastic modulus and high damping capacity [1]. These properties promote bone regeneration and make them promising candidates for being used in load transfer implantology. The objective of the present work is to achieve a material with shape memory properties and/or low elastic modulus. The influence of cold work on the thermoelastic martensitic transformation and elastic modulus of the Ti-16.2Hf-24.8Nb-1Zr alloy has been investigated to determine optimal conditions. The homogenized vacuum arc melted button was heat treated at 1100°C during 2 hours and quenched. Samples of each alloy were microstructurally and mechanically characterized after being cold rolled from 5 up to 95%. The elastic response for each condition was evaluated by instrumented nanoindentation by using a Berkovich tip and a spherical tip. A decrease in elastic modulus was observed when increasing the cold work percentage. The lowest value, 44 GPa, similar to that of cortical bone, was found in the 95% cold worked condition.

Modeling Tensile-Torsion Response of Double Twisted Helical Yarns

2018 ◽  
Author(s):  
Roozbeh Dargazany ◽  
Jiaqi Lin ◽  
Hamid Mohammadi ◽  
Vahid Morovati
Keyword(s):  
Constitutive Model ◽  
Load Transfer ◽  
Mechanical Response ◽  
Elastic Response ◽  
Hierarchical Architecture ◽  
Helical Structures ◽  
Deformation Regime ◽  
Deformed State ◽  
Multi Level ◽  
Induced Changes

Multi-level helical twisted structures represent an example of how natural design achieved an optimized approach for creating a tough and strong fiber from often weak and soft microscale yarns through a hierarchical architecture. In this work, a constitutive model is presented to describe the load transfer within a double twisted helical structures in large deformation regime. The model aims to establish the torsion-tensile properties of fibers as an assembly of twisted yarns and filaments. The model associates the fiber response to the mechanics and the geometry of yarns in the deformed state. In this work, we mainly focus on elastic response of the material and thus inelastic damages were not considered. We modeled the inter-yarn forces that can cause friction. By considering the deformation induced changes in the geometry of constituents, the model describes the influence of the fiber composition parameters such as helical angel of the filaments, prestretch, pretwist of the yarns and the inter-yarn frictions, on the mechanical response of fibers. The model provides a detailed outlook into load transfer within fibers which helps us understand how to design fibers with certain performance.

Energy Loss in an Analytical Membrane Tire Model

1977 ◽  
Vol 5 (3) ◽  
pp. 136-151 ◽  
Author(s):  
J. T. Tielking ◽  
R. A. Schapery
Keyword(s):  
Power Loss ◽  
Load Transfer ◽  
Flat Surface ◽  
Transfer Functions ◽  
Rolling Resistance ◽  
Elastic Response ◽  
Tire Model ◽  
The Finite Element Method ◽  
Low Loss ◽  
Static Loads

Abstract Energy dissipation is calculated from the contact deformation of a rolling toroidal membrane tire model. The method of dissipation analysis developed here can be used with other structural representations, including those based on the finite element method. The membrane tire model is inflated, loaded, and rolling on a frictionless, flat surface. The membrane material is assumed to be isotropic and neohookean under static loads and to exhibit a low loss tangent. The assumption of a low loss material permits viscoelastic power loss to be calculated from load transfer functions derived from the elastic response of the tire model. The power loss calculation is used to predict rolling resistance and contact patch shift.

On application of catenary principles to sandwich structure design—Sandwich/ catenary hybrid beams under uniformly distributed load

2017 ◽  
Vol 22 (2) ◽  
pp. 127-155
Author(s):  
Jørgen Asbøll Kepler
Keyword(s):  
Sandwich Structure ◽  
Load Transfer ◽  
Equilibrium Shape ◽  
Sandwich Beam ◽  
Structure Design ◽  
Face Sheet ◽  
Elastic Response ◽  
Distributed Load ◽  
Uniformly Distributed Load ◽  
Hybrid Beams

Application of catenary principles to sandwich structure design, whereby one face sheet follows the equilibrium shape of a catenary according to the applied load, is investigated. The difference between load transfer through a sandwich beam and through a catenary is outlined. An initial comparison between an inclined elastic string and a sandwich core under shear deformation provides an indication of the potential stiffness advantages of catenary design. A stiffness comparison is made between an ordinary sandwich beam with thin, parallel face sheets, a catenary suspended by the end-points, and a sandwich/catenary hybrid. It is demonstrated that, for mass parity and a uniformly distributed load, and depending on the constituent materials moduli, the sandwich/catenary hybrid may be designed for superior stiffness. A numerical modeling method is outlined for evaluating the deflection of a catenary, and subsequently expanded to predict deflection of a sandwich/catenary hybrid beam. The method is verified through comparison with experimentally measured deflection. It is demonstrated that first-order shear deformable theory, commonly applied to sandwich structures, is inherently unsuited for describing the elastic response of sandwich/catenary hybrids. For a typical range of face-sheet/core moduli, comparisons of relative stiffness for parallel-face sandwich beams and sandwich/catenary hybrid beams are calculated over a range of core heights, for equivalent core height and equivalent core volume.

Preparation of Electron Transparent Metal-Matrix Composites

1968 ◽  
Vol 26 ◽  
pp. 334-335 ◽  
Author(s):  
M. R. Pinnel ◽  
A. Lawley
Keyword(s):  
Stainless Steel ◽  
Load Transfer ◽  
Volume Fraction ◽  
Steel Wire ◽  
Initial Step ◽  
Interfacial Region ◽  
Matrix Composites ◽  
Specific Test ◽  
The Matrix ◽  
The One

Numerous phenomenological descriptions of the mechanical behavior of composite materials have been developed. There is now an urgent need to study and interpret deformation behavior, load transfer, and strain distribution, in terms of micromechanisms at the atomic level. One approach is to characterize dislocation substructure resulting from specific test conditions by the various techniques of transmission electron microscopy. The present paper describes a technique for the preparation of electron transparent composites of aluminum-stainless steel, such that examination of the matrix-fiber (wire), or interfacial region is possible. Dislocation substructures are currently under examination following tensile, compressive, and creep loading. The technique complements and extends the one other study in this area by Hancock.The composite examined was hot-pressed (argon atmosphere) 99.99% aluminum reinforced with 15% volume fraction stainless steel wire (0.006″ dia.).Foils were prepared so that the stainless steel wires run longitudinally in the plane of the specimen i.e. the electron beam is perpendicular to the axes of the wires. The initial step involves cutting slices ∼0.040″ in thickness on a diamond slitting wheel.

Deformation at interfaces of Ti-6Al-4V/SiC fiber composites

1992 ◽  
Vol 50 (1) ◽  
pp. 158-159
Author(s):  
Warren J. Moberly ◽  
Daniel B. Miracle ◽  
S. Krishnamurthy
Keyword(s):  
Thermal Stresses ◽  
Load Transfer ◽  
Coefficient Of Thermal Expansion ◽  
Hot Isostatic Pressing ◽  
Matrix Composites ◽  
Ongoing Research ◽  
Aerospace Applications ◽  
Sic Fiber ◽  
The Matrix ◽  
Intermetallic Matrix Composites

Titanium-aluminum alloy metal matrix composites (MMC) and Ti-Al intermetallic matrix composites (IMC), reinforced with continuous SCS6 SiC fibers are leading candidates for high temperature aerospace applications such as the National Aerospace Plane (NASP). The nature of deformation at fiber / matrix interfaces is characterized in this ongoing research. One major concern is the mismatch in coefficient of thermal expansion (CTE) between the Ti-based matrix and the SiC fiber. This can lead to thermal stresses upon cooling down from the temperature incurred during hot isostatic pressing (HIP), which are sufficient to cause yielding in the matrix, and/or lead to fatigue from the thermal cycling that will be incurred during application, A second concern is the load transfer, from fiber to matrix, that is required if/when fiber fracture occurs. In both cases the stresses in the matrix are most severe at the interlace.

Definition of load transfer curves of piles in granitic residual soil

Geotecnia ◽  
2014 ◽  
Vol 130 ◽  
pp. 79-99
Author(s):  
David Jorge Pereira Fernandes ◽  
◽  
<br>António Viana da Fonseca ◽  
Keyword(s):  
Load Transfer ◽  
Residual Soil ◽  
Definition Of

scholarly journals Modelling of a Partially Loaded Road Tanker during a Braking-in-a-Turn Maneuver

Actuators ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 45 ◽  
Author(s):  
Frank Otremba ◽  
José Romero Navarrete ◽  
Alejandro Lozano Guzmán
Keyword(s):  
Road Safety ◽  
Load Transfer ◽  
Dynamic Interaction ◽  
Performance Measure ◽  
Lateral Stability ◽  
Safety Level ◽  
Factors Associated ◽  
Braking System ◽  
Factors Influencing ◽  
Fill Level

Road safety depends on several factors associated with the vehicle, to the infrastructure, as well as to the environment and experience of vehicle drivers. Concerning the vehicle factors influencing the safety level of an infrastructure, it has been shown that the dynamic interaction between the carried liquid cargo and the vehicle influences the operational safety limits of the vehicle. A combination of vehicle and infrastructure factors converge when a vehicle carrying liquid cargo at a partial fill level performs a braking maneuver along a curved road segment. Such a maneuver involves both longitudinal and lateral load transfers that potentially affect both the braking efficiency and the lateral stability of the vehicle. In this paper, a series of models are set together to simulate the effects of a sloshing cargo on the braking efficiency and load transfer rate of a partially filled road tanker. The model assumes the superposition of the roll and pitch independent responses, while the vehicle is equipped with Anti-lock braking System brakes (ABS) in the four wheels. Results suggest that cargo sloshing can affect the performance of the vehicle on the order of 2% to 9%, as a function of the performance measure considered. A dedicated ABS system could be considered to cope with such diminished performance.

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