Model Test and Numerical Simulation of Grouted Connections for Offshore Wind Turbine Under Static Axial Load

Weiqiu Zhong,Lintao Li,Deming Liu,Tao Yang,Wuxu Li

doi:10.3390/jmse8070543

Abstract

The bearing capacity of the grouted connections is investigated through the model test and numerical simulation with two rates (low and high) and four kinds of specimens: shorter without shear keys, shorter with shear keys, longer with shear keys, and conical with shear keys. It reveals that the bearing characteristics of the specimen of longer with shear keys is worse than the specimen of conical with shear keys, but better than the specimen of shorter with shear keys. Moreover, the bearing characteristics of the specimen of shorter without shear keys is the worst one.

Highlights

The world’s offshore wind energy resources can be prepared in a huge amount [1–5]
(1) The damage to test piece A begins with the bond failure between the outer casing and the grouted stone body and, the overall outer casing slides down, once the damage begins, the ultimate bearing capacity is reached; (2) The short shear key test piece B is severely damaged around the shear key and both ends are more serious than the middle part; (3) Test piece C and the key test piece D are broken by the chipping of the grouted stone body between the shearing keys, the longer specimen deviated from the middle position to the two ends and the taper connection diameter transition was seriously damaged
The conclusions are as follows: (1) under the axial load, the axial bearing capacity of the specimen A is the lowest and the beginning of the failure means the termination of the failure, which is an obvious brittle failure

Summary

Introduction

The world’s offshore wind energy resources can be prepared in a huge amount [1–5]. While onshore wind power has rapidly improved, the development of offshore wind power has begun. The transitional form of marine structures and basic connections have achieved rapid development, and has been applied internationally [6–8].The structure of the grouting connection has the advantages of reasonable force and economy, so it is commonly used in the offshore wind turbine foundation. The force behavior of this type of connection has been studied internationally, and its results have mainly focused on grouting [9–14] with low-stress performance, and has formed a clear design specification guide design [15–19]. There are few studies on the connection form using high-performance grout, and there are fewer studies on experimental performance [20–26]. Based on the actual need of some offshore wind farm development projects in China, this study conducted axial static load tests and numerical simulation on the offshore joints of high-performance grouting, which can provide a reference for the design of similar projects

Test Piece Design

The upper end of 450 The lower end of 548

Measurement Content and Test Process

Numerical Simulation

Conclusions