Performance of angle shear connectors for U-shaped steel concrete infilled composite beams.

The current design codes i.e. AISC 360-16, CSA-S16-19, EC-04 etc. provide empirical relationships to estimate the capacity of shear connectors which were developed based on pushout tests of headed studs and channels connectors in exposed type sections. Therefore, these equations may result inaccurate predictions for strength of connectors in infilled-type sections. This study presents a detailed experimental study investigating the performance of angle connectors in composite sections. The testing program consisted two series of pushout tests. A total of 36 specimens were tested, considering the influence of several important parameters i.e. the length (Lc), height (hc), and web-thickness (tw) of angle connector, length of the weld (w) and the direction of shear connector (forward/backward) etc. The tests results demonstrated that with increasing connector height hs, and thickness, the maximum load Pmax and slip δu were increased. The connector direction didn't change much the load-slip behavior. The prediction accuracy of the existing shear capacity models was evaluated by comparing the predictions with experimental results. The current equations were noticed to be highly inconsistent in predicting the shear capacity of angle connectors, especially in case of infilled type sections. When the entire length of connector was taken as the effective length, the models overestimated the shear capacity. While in case when the welding length was taken as effective length in calculations, the models underestimated the shear strength of angle connectors.

Transvenous embolization using the Amplatzer Vascular Plug II in patent ductus arteriosus concomitant with Stanford type B aortic dissection: A case report.

RATIONALE: Thoracic endovascular aneurysm repair (TEVAR) is commonly used to treat Stanford type B aortic dissections. However, coexistence of aortic dissection and patent ductus arteriosus (PDA) is an extremely rare phenomenon, and TEVAR alone is insufficient for treatment. Herein, a case of endovascular treatment in a patient with both aortic dissection and PDA is reported. PATIENT CONCERNS: A 31-year-old woman presented to the authors' hospital with chest pain extending to the back. At presentation, her blood pressure was 130/70 mm Hg. Her father, brother, and uncle were all diagnosed with aortic dissection. DIAGNOSES: Computed tomography (CT) revealed Stanford type B aortic dissection from the aortic arch to the infrarenal abdominal aorta; however, PDA was incidentally identified. INTERVENTIONS: TEVAR was immediately performed. Follow-up CT scan performed 2 months later did not reveal any thrombosis or remodeling of the false lumen, and the PDA remained open. Therefore, an additional PDA embolization procedure was performed using the Amplatzer Vascular Plug II via the transvenous route. OUTCOMES: On follow-up CT performed 6 months after PDA embolization, successful remodeling, and shrinkage of the false lumen were observed, and PDA closure was confirmed. LESSONS: If Stanford type B aortic dissection and PDA coexist, TEVAR alone may not be a sufficient treatment and additional PDA embolization may be required. In the present case, transvenous embolization of PDA using an Amplatzer Vascular Plug II was safe and effective.