TAILIEUCHUNG - Engineered Interfaces in Fiber Reinforced Composites Part 4

Tham khảo tài liệu 'engineered interfaces in fiber reinforced composites part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Engineered interfaces in fiber reinforced composites . Interlaminar fracture toughness . Delamination Delamination represents the weakest failure mode in laminated composites and is considered to be the most prevalent life-limiting crack growth mode in most composite structures. As such ever-increasing attention has been directed toward the understanding and characterization of delaminations of various natures and at 1 2 Normalised interface shear strength OJ OJ OJ w L. QJ tn cgj Fig. . Schematic drawing of transverse tensile test specimen. Fig. . Effect of the interface shear strength on mechanical properties of carbon fiber-epoxy matrix composites transverse tensile strength A maximum transverse tensile strain O transverse tensile modulus. After Madhukar and Drzal 1991 . Chapter 3. Measurements of interface interlaminar properties 75 free notch ply bonded bolted edge hole drop-off joint joint Fig. . Sources of delamination due to out-of-plane load from discontinuities in structure. After Wilkins et al. 1982 . the same time toward improving the durability of composites against interlaminar fracture. Delamination may be introduced during processing or subsequent service conditions. It may result from low-velocity impact from eccentricities in the structural load path or from discontinuities in structures which induce a significant out-of-plane stress as shown in Fig Wilkins et al. 1982 . These are i straight or ii curved near holes free edges iii ply terminations or ply drop for tapering the thickness iv bonded or co-cured joints v a bolted joint and vi a cracked lap shear specimen. All these cases the local stress near the discontinuities may be out-of-plane even if the loading at remote end is in-plane. Even in the absence of such discontinuities delamination can result from in-plane compressive loading causing local or global buckling to occur. In addition to mechanical loads the moisture and temperature may also induce interlaminar .