Experimental parametric investigation on the behavior of adhesively bonded CFRP/steel joints

This paper presents an extensive experimental and numerical study on the behavior of CFRP/Steel adhesively bonded double strap joints (DSJ). A total of 50 DSJ specimens were tested under static tensile loading. The digital image correlation (DIC) was used to measure the backface deformation. A total of six adhesives that feature different...

High performance and cost-effective hybrid steel/CFRP joints using bi-adhesive technique for the repair of metallic infrastructures

The use of the brittle adhesives commonly adopted in construction industry do not provide the best performance for steel structures. CFRP/Steel joint bonded with extremely tough adhesive achieve much higher strength and ductility. However, tough adhesives are not developed for the construction industry and their cost may question the...

Assessing stiffness degradation of stiffened composite panels in post-buckling compression-compression fatigue using guided waves

The application of structural health monitoring (SHM) in composite airframe structural elements under long-term realistic fatigue loading needs to consider the structural behavior on the global level, which is an intricate task. The overall structural stiffness is a key design parameter for composite structures and the stiffness degradation...

Impact damage of composite laminates with high-speed waterjet

Rain erosion may cause substantial damage to aircrafts during supersonic flight. Such event is investigated here via high-speed waterjet impact on composite laminates. An experimental setup is developed to produce waterjets with the speed up to 700m/s and a finite element model of the waterjet-composite impact event is established. The...

Modeling and imaging of ultrasonic array inspection of side drilled holes in layered anisotropic media

There has been an increase in the use of ultrasonic arrays for the detection of defects in composite structures used in the aerospace industry. The response of a defect embedded in such a medium is influenced by the inherent anisotropy of the bounding medium and the layering of the bounding medium and hence poses challenges for the...

Loading rate dependency of strain energy release rate in mode I delamination of composite laminates

This work aims at studying the loading rate dependency of mode I delamination growth in CFRPs, using typical fracture toughness analysis through both the R-curve and the crack tip opening rate. The average SERR is a method of data reduction based on energy balance which has been previously introduced to characterize delamination growth under...

A gaussian beam based recursive stiffness matrix model to simulate ultrasonic array signals from multi-layered media

Ultrasonic testing using arrays is becoming widely used to test composite structures in the Aerospace industry. In recent years, the Full Matrix Capture (FMC) technique has been implemented to extract the signals for post-processing to form an image. The inherent anisotropy and the layering of the structure pose challenges for the...

Effect of moisture on the adhesion of CFRP-to-steel bonded joints using peel tests

In this work, an experimental study has been carried out to evaluate the effect of salt water condition on the long-term adhesion of composite-to-metal bonded joints using peel tests. A new test configuration is tested via fully and partially immersed specimens with 500 mm length. Fracture surfaces of non-aged samples exhibited a cohesive...

Interlaminar adhesion assessment of carbon-epoxy laminates under salt water ageing using peel tests

The aim of this study is to assess the interlaminar adhesion of carbon-epoxy laminates under salt water condition. Carbon-epoxy laminate specimens were immersed in a salt water tank for 60 days. Some specimens were then dried at<br/>room temperature for 280 days, until recovering their initial weight. Specimens were tested using the composite...

Simulation and detection of flaws in pre-cured CFRP using laser displacement sensing

The novelty of the research is the detection of different types of flaws in the prepreg carbon fibre-reinforced fibres (CFRP) layup compared to in cured products. This paper presents the development of a new method for in situ detection of prepreg CFRP production flaws combining laser displacement sensors and analytical modelling. Experimental...