Polymethylmethacrylate (PMMA) has been widely used as transparency in aerospace and automobile engineering to enhance structural reliability under impact loading such as bird strike events. This study investigates the confined compressive behaviour of PMMA at quasi-static 0.01 s⁻¹, medium rate 1-100 s⁻¹ and intermediate strain rates 100-1000 s⁻¹ from room temperature to elevated temperatures. Constant intermediate strain rate loading is achieved by using pulse shaping technique on a bespoke in-house developed split Hopkinson compression bar equipped with a high-speed camera and an environmental chamber. The material presents significant strain rate, temperature and pressure sensitivities. The failure mode at intermediate strain rate changes from brittle fragmentation without confinement to adiabatic shear banding with medium lateral confinement (65.3 MPa), which can be seen from the post-peak slope in the constitutive behavior, melting flow PMMA filaments observed in high speed photography and microstructural analysis. A series of intermediate strain rate experiments at elevated temperatures indicate that the higher temperature results in ductile failure for corresponding pressures. The temperature and strain rate dependent Drucker-Prager (DP) model is found to describe the response of PMMA. The brittle-ductile transition and pressure dependent model provide a better understanding of PMMA at intermediate strain rates, which is appropriate for engineering applications.

聚甲基丙烯酸甲酯 (PMMA) 已被广泛用作航空航天和汽车工程中的透明材料，以提高在冲击载荷（例如鸟类撞击事件）下的结构可靠性。本研究调查了准静态 0.01 s ^-1、中等速率 1-100 s ^-1和中等应变速率 100-1000 s ^-1下 PMMA 的受限压缩行为从室温到高温。通过在定制的内部开发的分裂式霍普金森压缩杆上使用脉冲整形技术来实现恒定的中间应变率加载，该压缩杆配备有高速摄像机和环境室。该材料具有显着的应变率、温度和压力敏感性。中等应变速率下的破坏模式从没有约束的脆性破碎变为具有中等横向约束（65.3 MPa）的绝热剪切带，这可以从本构行为中的峰后斜率看出，在高速摄影中观察到熔融流动 PMMA 细丝和微观结构分析。在升高的温度下进行的一系列中间应变率实验表明，较高的温度会导致相应压力的延性破坏。发现温度和应变率相关的 Drucker-Prager (DP) 模型可以描述 PMMA 的响应。脆韧转变和压力相关模型提供了对中等应变率下 PMMA 的更好理解，这适用于工程应用。