Additively manufactured tensile ring-shaped specimens for pipeline material fracture examination - influence of geometry

In order to define a procedure for integrity assessment of pipelines and determining the fracture mechanics parameters, new type specimen with sharp notch, Pipe Ring Notched Tension (PRNT) specimen, is tested. The aim study determine influence geometry (cylindrical shape, as well number length stress concentrators) on parameters such force, Crack Mouth Opening Displacement CMOD, Tip CTOD J integral. specimens were fabricated by an additive production method - selective laser sintering (SLS). EOS Formiga P100 machine used, material polyamide PA12. addition specimens, Single Edge (SENT) identical cross section also considered. All tested universal tensile testing machine. A tool specially designed apply contact pressure inner walls in tension direction was simulating internal pressure. For field displacement strain surface samples that occur during loading, Aramis GOM 2M optical measurement system used. applied determination parameters: CMOD (based δ5 concept). examination properties additively manufactured PA12, main topic this work development non-standard procedure, which will be subsequently cut from metallic or non-metallic pipes. As important part calculation conducted based results presented here.