Experimental an‎d numerical study of dynamic fracture toughness of polymer matrix composites with split hopkinson pressure bar (SHPB)

2/17/2027 12:00:00 AM

Understan‎ding the mechanical properties an‎d fracture behavior of polymer matrix composites under dynamic loading conditions (high strain rates) remains one of the fundamental challenges in structural design an‎d lifetime prediction. Depending on the strain rate level, various experimental techniques, such as the Hopkinson bar apparatus, can be employed to characterize the mechanical properties. In this study, an experimental methodology is proposed for measuring the crack growth resistance (R-curve) of polymer matrix composites subjected to dynamic compressive loading. In the data analysis process, a combination of energy release rate concepts, the size effect law, an‎d the crack resistance curve is utilized. In the first stage, the energy release rate of a cross-ply composite laminate containing two edge cracks is determined using a parametric finite element model. In the second stage, this energy release rate is employed to establish a relationship between the crack resistance curve an‎d the size effect law. Subsequently, experimental tests are conducted on scaled specimens, an‎d the size effect law is quantitatively extracted to provide the final data required for determining the crack resistance curve. To this end, glass/epoxy specimens with two edge cracks were fabricated an‎d tested in six different sizes. The experimental program included a quasi-static reference test as well as dynamic compressive tests using a Hopkinson pressure bar apparatus at a strain rate of 180 s⁻¹. The crack resistance curves under both dynamic an‎d quasi-static loading conditions were derived based on quasi-static fracture mechanics theory. The results indicate that the stable intralaminar Mode I fracture toughness of glass/epoxy composites under compressive loading exhibits a strong dependence on the strain rate an‎d increases with increasing strain rate.

دستگاه فشاري هاپكينسون , كامپوزيت هاي زمينه پليمري , اثر اندازه , چقرمگي شكست ديناميكي

Split Hopkinson Pressure Bar (SHPB) , polymer matrix composites , size effect , Dynamic fracture toughness

Abolfazl zare Ebrahim abad

Fathollah Taheri Behrooz