超声-力耦合作用下压制成型中PBX炸药颗粒细观力学行为及其作用机制研究

The formation of the qualified densification and density uniformity is difficult in the casting of PBX parts, which is a key performance index in the development of large-scale complex parts required for high-performance strategic weapon equipment and advanced warhead in our country. Exerting ultrasonic disturbance to the solidification of PBX parts is a novel process approach for improving the molding density distribution, enhancing molding quality and promoting weapons overall performance. In this application,SEM、XPS and AFM testing were carried out to detect the structure, morphology, composition and microstructure changes of crystal, binder and particle before and after ultrasound vibration. In addition,the displacement vector plot was obtained using the DIC, and three dimension microstructure and micromechanical properties of PBX particles under different ultrasonic vibration-mechanical coupling conditions were studied using μCT and compressed testing. A multiscale modelling of the mesastructure of PBX materials in ultrasonic vibration-mechanical coupling pressing process was established, what is more, the constitutive relationship of ultrasonic parameter and density and density uniform ity of PBX parts was studied.Based on coordination mechanisms of ultrasonic vibration and pressure loading and the summarization of experimental phenomena, combining theoretical knowledge of ultrasound volume effect, surface effect and resonance effects, the dominant the effect rules and function mechanism of ultrasonic field on the solidification of PBX parts at different solidification stages was revealed comprehensively through the mathematical calculations and theoretical analysis. This will provide an important academic guidance for designing, optimizing and studying the application of PBX materials in ultrasonic vibration-mechanical coupling pressing process.

炸药件成型高致密化及密度均匀性是提升我国高性能战略武器及先进战斗部装药性能的关键指标。对炸药压制成型过程施加超声波振动是改善成型密度分布及提高成型品质的一个新的技术途径。本项目拟通过SEM、XPS、AFM等表征手段，研究晶体、粘结剂及颗粒在超声-压制作用前后结构、形貌、组分等微观变化，并借助DIC对细观变形场进行分析，采用μCT及压缩实验对不同耦合条件下PBX的三维细观结构及力学响应进行分析，研究PBX在超声-力耦合作用下的微观结构演变及力学行为规律。建立超声-力耦合作用下反映炸药细观结构特征的多尺度模型，研究超声参量与成型件密度及均匀性的本构关系，结合超声振动与力载荷的协调机制及超声体积效应、表面效应及谐振效应等理论,揭示超声场耦合作用对炸药颗粒压制过程不同阶段的微细观结构演变的主导作用机制和规律。本项目的研究对炸药超声-力耦合压制成型的设计、优化以及应用具有重要的理论指导作用。

炸药件成型高致密化及密度均匀性是提升我国高性能战略武器及先进战斗部装药性能的关键指标。对炸药压制成型过程施加超声波振动是改善成型密度分布及提高成型品质的一个新的技术途径。本项目通过研究，掌握超声-力耦合系统设计、换能器、模具及控制软件的设计，通过有限元方法对超声加载方式及模具振动模态仿真优化；掌握炸药在超声-力耦合作用下的宏观力学响应研究；掌握炸药颗粒在超声-力耦合边界条件下的作用关系及微细观结构演变规律，建立超声-力耦合作用下反映炸药细观结构特征的模型，研究超声参量与成型件密度及均匀性的本构关系，结合超声振动与力载荷的协调机制及超声体积效应、表面效应及谐振效应等理论,揭示超声场耦合作用对炸药颗粒压制过程不同阶段的微细观结构演变的主导作用机制和规律。揭示其在超声-力耦合作用下的细观力学响应及作用机制。基于以上研究结果，在国内外学术刊物上发表论文3篇，申请专利2项，参加国内外学术交流4次，培养青年科技人才或硕士研究生2名。本项目的研究对炸药超声-力耦合压制成型的设计、优化以及应用具有重要的理论指导作用。