Co-authors​ :

 Kaveh SHAHIDI (TURKEY), Nuri ERSOY (TURKEY), Gulum TANIRCAN (TURKEY), Hakan MIS  

This study addresses the research gap in the earthquake resistance of composite pipelines, specifically focusing on developing an earthquake-resistant glass fiber-reinforced composite (GRP) pipe connection system. Driven by the absence of prior research in this domain, the project seeks to devise an innovative angular deflection solution for GRP pipes, aligning with earthquake-resistant guidelines, addressing axial, transverse, or rotational deformation of the joint based on the pipe's alignment with ground movement, ensuring complete flexibility. The omission of bolts in the joints further simplifies the assembly and disassembly process of these specific designs. The primary objective is to formulate a sleeve capable of withstanding seismic loads, incorporating research and development components. The research is structured around two main facets: 1) Mechanical characterization of composite materials and rings derived from filament-wound pipes, and 2) Structural optimization of earthquake-resistant composite Pipes and Joints. The mechanical characterization involves a systematic series of tests and procedures to ascertain precise material properties for Glass Fiber-Reinforced Polymer (GFRP) pipes, especially when mechanical properties are uncertain. Notably, ring compression tests on filament-wound pipe rings demonstrated successful predictions of stiffness and strength using finite element models. The methodology integrates composite micromechanics theories and existing literature to establish an initial reference, employing an iterative process with the stress homogenization method. Ensuring consistency, this method is applied to standardized test results from specimens in a single pipe batch. Validation of determined properties occurs through comparing and verifying simulated Finite Element outcomes with experimental data obtained from actual tests. Considering the composite components 'manufacturability, the pipes and joints have been conclusively designed, see Figure 1. Optimization is accomplished through stress analysis utilizing Finite Element Analysis, entailing the determination of wall thicknesses and enhancing the locations and geometries of sealing rings and lock rings. The proposed pipe joint model is anticipated to advance the engineering design of earthquake-resistant composite pipes. Simulations demonstrate the optimized design's resilience against faulting, liquefaction, landslides, mining, dewatering, and construction activities. This information is valuable for designing and assessing pipelines' risk of significant ground deformation.