tailieunhanh - Encyclopedia of Smart Materials (Vols 1 and 2) - M. Schwartz (2002) WW Part 5

Tham khảo tài liệu 'encyclopedia of smart materials (vols 1 and 2) - m. schwartz (2002) ww part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Figure 14. Schematic of the evolution of tensile fiber damage in aligned fiber composites a fiber break with interfacial debonding b fiber break expanding matrix crack c matrix crack with fiber bridging and d a compilation of a b and c resulting in a damage zone. Figure 15. Weibull cumulative probability distribution function G a describing variations in fiber strength 1 Fibers do not exhibit a wide variability in fracture strength between 0 and 1 where is the occurrence of tensile failure in 50 of fibers and 2 a wide variation exists and is statistically described by a standard deviation as indicated with vertical lines. Below the lower strength limit all fiber same amount of elongation and remain uni lower strength limit is exceeded the weake containing internal flaws leading to reduced sections break in succession and the load ferred to the surviving fibers. Complete fract dle occurs when the upper strength limit is Several tensile dominated failure modes sider the fiber-and-fiber bundle failure pr they are bound by a matrix include the we ure mode cumulative weakening failure mo propagation failure mode and cumulative mode. The weakest link failure mode ass trophic failure with the occurrence of a sin small number of independent fiber breaks this mode of failure is an unlikely character the stress level at which weakest link even not be sufficient enough to invoke comp failure. The cumulative weakening failure mode an extension of the weakest link failure modi acterization of this mode a fiber fracture si distribution of stress near the site. As mon along a fiber they tend to have a statistical s bution that is equivalent to the distribution the fiber. Failure is thought to occur when the section of a lamina is weakened to the poi able to support any further increments in l argument to acceptance of this mode entire terization of failure is that no consideration effects on neighboring fibers and flaws. It is well known that the effects of stress at .