Towards understanding residual strength and damage evolution in damaged composite laminates

Fibre reinforced polymer composites have found increasing use in aircraft structures. This means that fleet managers need damage assessment tools for such materials, in order to decide on appropriate sustainment strategies. Developing such tools is hindered by the difficulty of generalising from lab tests to predict the behaviour of full-scale...

Compression after impact fatigue damage growth in CFRP – what does no-growth really mean?

Impacts on carbon fiber reinforced composites (CFRP) can produce a complex internal damage comprising multiple delaminations, which is hard to detect from visual inspection. This situation is known as barely visible impact damage (BVID). Considering that every airplane faces several impacts during its operational life, and that the majority of...

Measurement of damage growth in ultrasonic spot welded joint

Ultrasonic spot welding is a joining technique for thermoplastic composites with great potential regarding processing speed and cost. To investigate the damage tolerance and possible inherent damage arresting behavior of multi-spot welded joints, a technique is necessary to measure damage growth in the joints under cyclic loading. Visual...

Capacity of prestressed concrete bridge decks under fatigue loading

In The Netherlands, existing slab-between-girder bridges with prestressed girders and thin transversely prestressed concrete decks require assessment. The punching capacity was studied in a previous series of experiments, showing a higher capacity thanks to compressive membrane action in the deck. Then, concerns were raised with regard to...

Fatigue life of post-buckled composite structures

The fatigue life prediction of post-buckled composite structures represents still an unresolved issue due to the complexity of the phenomenon and the high costs of experimental testing. In this paper, a novel numerical approach, called “Min-Max Load Approach” is adopted to analyze the behavior of a single-stringer composite specimen with an...

Fatigue crack propagation in composite laminates by a novel approach based on the S-N diagrams

This paper focuses on a novel numerical formulation based on cohesive elements and S-N diagram to simulate fatigue-driven delamination in composite laminates. The constitutive model adopts a two-parameters heuristic equation, which coefficients are evaluated using an idealization of the S-N diagram rather than the more commonly used Paris law....

Committee III.2: Fatigue and Fracture

Concern for crack initiation and growth under cyclic loading as well as unstable crack propagation and tearing in the ship and offshore structures. Due attention shall be paid to the suitability and uncertainty of physical models and testing. Consideration is to be given to practical application, statistical description and fracture control...

Modeling fatigue-driving delamination using a thick level set interface model

This paper presents a new discontinuous damage model for simulating fatigue-driven delamination in composites. Fatigue models commonly describe crack growth using the Paris law which provides the link between the energy released due to delamination and the crack growth rate. A core issue in implementing the Paris law is to accurately compute the...

Static and fatigue performance ofthick laminates test design and experimental compression results

The aim of this work is to study the thickness effect in static and fatigue tests of glass-fibre unidirectional compression coupons. For this purpose, the self-heating effect, the effect of specimen geometry, and the influence of the manufacturing processes have been minimized. A scaled thickness compression coupon has been designed with the...