The combination of materials to form a new material system with enhanced material properties is a well documented historical fact. For example, the ancient Jewish workers during their tenure under the Pharaohs used chopped straws in bricks as a means of enhancing their structural integrity. The Japanese Samurai warriors were known to use laminated metals in the forging of their swords to obtain desirable material properties. Even certain artisans from the Mediterranean and Far East used a form of composite technology in molding art works which were fabricated by layering cut paper in various sizes for producing desired shapes and contours.

Introduction To Composite Materials

This paper is a review of low-velocity impact responses of composite materials. First the term ‘low-velocity impact’ is defined and major impact-induced damage modes are described from onset of damage through to final failure. Then, the effects of the composite's constituents on impact properties are discussed and post-impact performance is assessed in terms of residual strength.

Review of low-velocity impact properties of composite materials

A critical review of recent research on functionally graded plates

Literature survey of contact dynamics modelling

A review of mechanical drilling for composite laminates

1. Introduction 2. Contact laws 3. Impact dynamics 4. Low velocity impact damage 5. Damage prediction 6. Residual properties 7. Ballistic impact 8. Repairs 9. Impact on sandwich structures References.

Impact on Composite Structures

Impact on Laminated Composite Materials

Impact damage in structures made out of composite materials is a major concern since such damage can be introduced during the life of the structure, and its mechanical properties can be drastically reduced as a result. In a previous review of the literature on impact on composite materials, this author considered 285 published before 1989. In this article over 300 articles most of which appeared after 1989 are reviewed. These figures indicate that this is a very active area of research, and the present paper seeks to present a comprehensive view of the latest developments. Taken together, these two reviews present a comprehensive view of the state of knowledge in the area. Most the current research effort is focused on low velocity impact damage and, in particular, the damage predictions and the evaluation and prediction of residual properties of damaged laminates. A significant number of papers deal with ballistic impacts on laminated composites and the use of composite materials in designing light armor.

Impact on Laminated Composites: Recent Advances

An investigation of the low velocity impact load level at which a composite laminate will delaminate is presented. The delamination threshold load is described as the load level, obtained from the load–time history or load–displacement plot, at which a sudden load drop occurs due to specimen stiffness loss as a result of laminate level damage. Approximately 500 low velocity impact load–time histories from the Air Force Research Laboratory (AFRL) Low Velocity Impact Database are used to investigate the delamination threshold load. The database contains laminate impact test data for graphite/epoxy (AS4/3501-6), graphite/PEEK (AS4/APC-2), and graphite/BMI (IM7/5260) material systems. The delamination threshold load observations are compared to C-scan damage measurements of impacted specimens to determine if the sudden load drop corresponds to delamination development.

Serge Abrate

Papers

Impact on Composite Structures

Impact on Laminated Composite Materials

Impact on Laminated Composites: Recent Advances

Delamination threshold loads for low velocity impact on composite laminates

Modeling of impacts on composite structures