# Research on the Adhesive Strength of Different Bonding Structures for Modular Wind Turbine Blades

## TL;DR

This study examines different adhesive joint designs for modular wind turbine blades to improve their strength and durability.

## Contribution

The study identifies the double-slope joint as the most effective adhesive structure for modular wind turbine blades.

## Key findings

- The double-slope joint achieved the highest peak load of 1017.26 N and delayed damage evolution.
- Numerical simulations showed the double-slope joint had the highest predicted peak loads in flapwise and edgewise loading.
- The findings provide theoretical support for improving blade structural design and adhesive joint performance.

## Abstract

To address the manufacturing and transportation challenges of large wind turbine blades, adhesive joints in modular blades have become a research focus. This study investigates six typical adhesive joint configurations for CFRP laminates using quasi-static three-point bending experiments and cohesive-zone finite element simulations. The adhesive interface is modeled with a bilinear traction–separation law using zero-thickness cohesive elements to capture damage initiation and propagation. Among the six designs, the double-slope joint exhibits the best static performance, achieving the highest peak load of 1017.26 N and showing delayed damage evolution. The superiority of the double-slope design is further examined at the blade level via a numerical cantilever model of equal-section modular blade segments under flapwise and edgewise loading. The predicted peak loads reach 9.82 × 107 N (flapwise) and 5.51 × 107 N (edgewise), ranking the double-slope joint highest among the investigated configurations. The findings show that the double-slope joint improves load capacity and resistance to degradation, and reveal failure mechanisms of adhesive joints, providing theoretical support for blade structural design.