Relationship between mechanical-property and energy-absorption trends for composite tubes
U.S. Army helicopters are designed to dissipate prescribed levels of crash impact kinetic energy without compromising the integrity of the fuselage. Because of the complexity of the energy-absorption process it is imperative for designers of energy-absorbing structures to develop an in-depth understanding of how and why composite structures absorb energy. A description of the crushing modes and mechanisms of energy absorption for composite tubes and beams is presented. Three primary crushing modes of composite structures including transverse shearing, lamina bending, and local buckling are described. The experimental data presented show that fiber and matrix mechanical properties and laminate stiffness and strength mechanical properties cannot reliably predict the energy-absorption response of composite tubes.
Experimental study on crushing characteristics of brittle fibre/epoxy hybrid composite tubes
The collapse characteristics and energy-absorption capability of three kinds of hybrid composite tubes, G827-G803/3234, G827-G803/5224 and G827-759/5224, are studied in the present article. Each of the specimens containing two kinds of brittle fibre has been examined by both axial quasi-static and impact crushing test. The effects of fibre type, fibre content and loading conditions on the crushing-failure characteristics, peak load and energy-absorption capability are discussed. The test results show that for G827-G803/3234 tubes, the crushing failure mode is changed from the splaying mode to the fragmentation mode when quasi-static loading is changed to impact loading, while for others there is no such characteristic. The fibre type and fibre content have significant influences on peak load. It is observed that the tubes containing only one kind of brittle fibre have lower peak load than the ones containing two kinds of fibres with approximately equal hybridisation contents. The energy-absorption capability can be improved by reasonably hybridising with two kinds of brittle fibres. Generally, the energy-absorption capability is reduced remarkably under impact crushing test in comparison with that under quasi-static test.
Hispanic marketing : connecting with the new latino consumer
* Cultural Marketing: A new understanding * The Composition of the Hispanic/Latino market * The Latino Essense of "Hispanic" * Language Considerations in Marketing to US Hispanics * Enculturation, Acculturation, and Assimilation: A Bicultural Horizon * Latino Subjective Culture: Insights for Positioning * Culturally Informed Research among Latinos * The U.S. Hispanic Marketing Industry * The Digital World of U.S. Latinos * Latino Consumers and the Future of U.S. Marketing