SBIR Phase I: Characterization of a novel macro-composite material with application to impact-recovery structures

小型企业创新研究(SBIR)第一阶段项目将调查为一种新型宏观复合材料结构的弹性性能和强度建立可靠数值的可行性，并调查这种材料在冲击恢复结构中的应用。拟议的研究计划将包括三个主要组成部分：机械性能、设计公式和制造技术。采用经典细观力学和基于有限元分析的方法来获得弹性模量值，并将其与实验测得的票面值进行比较。强度和失效模式也将从试件试验中获得，并将评估应变不变失效理论对宏观复合材料的适用性。然后，将建立一个基于力学的程序来设计由宏观复合材料构成的圆柱管。这些管子在承受弯矩时必须椭圆形并逐渐坍塌，但在卸载后又原封不动地恢复到原来的形状。将评估几种低成本的管材制造工艺，包括拉挤和挤压。宏观复合材料结构在管材结构中的应用已被证明具有显著的结构冲击恢复能力。这种材料和结构技术的主要商业应用已经确定。通过使用这种宏观复合材料来减少车辆碰撞和环境退化对路边结构造成的大量破坏，每年的维护资金将被腾出用于更紧迫的公共基础设施维修和恢复需求。

The Small Business Innovation Research (SBIR) Phase I project will investigate the feasibility of establishing reliable values for the elastic properties and strength of a novel macro-composite material construction, as well as investigate the application of this material to impact-recovery structures. The proposed research program will have three major components: mechanical properties, design equations, and manufacturing technology. Both classical micromechanics and a finite element analysis-based method will be employed to obtain the elastic moduli, which will be compared with experimentally-measured coupon values. Strength and failure modes will also be obtained from coupon tests, and the applicability of the strain invariant failure theory to the macro-composite will be evaluated. A mechanics-based procedure will then be established for the design of cylindrical tubes constructed from the macro-composite. These tubes must ovalize and gradually collapse when subjected to bending moments, yet return undamaged to the original configuration upon removal of loads. Several low-cost manufacturing processes for the tubes will be evaluated, including pultrusion and extrusion.The application of the macro-composite material construction to tubular structures has been demonstrated to result in a significant structural-impact recovery capability. A major commercial application for this material and structural technology has been identified. By using the macro-composite material to reduce the large amounts of damage to roadside structures caused by both vehicle impacts and environmental degradation, annual maintenance dollars will be freed up for more urgent public infrastructure repair and rehabilitation needs.