Evaluation and Repair of Wrought Iron and - Purdue e-Pubs ...

121A study conducted at Iowa State University in 1976 on the strength of eyebarconnections included some fatigue testing on damaged and undamaged eyebars. Fatiguetests were completed on twenty three undamaged eyebars and nine damaged and repairedeyebars. Of the undamaged eyebars, twenty one failed in one of the eyes of the eyebar.Of the damaged and repaired eyebars only two fractured in the presence of a repair andthe rest failed in the eyes (Elleby, 1976).The results from testing completed in this study and from the testing at Iowa StateUniversity support the need to check for fatigue cracking at the holes of the eyebars.This is especially true since these members are considered to be fracture critical and havebeen in service for such a long time.Regardless of the geometry, existing eyebars tend to perform well and fail outsideof the connection area under static loading conditions. Evidence of this can be seen inthe testing that was completed during this research study. Four eyebar connections werestatically tested in tension until they failed. All of the eyebar connections failed outsideof the connection detail area.Testing that was completed at Iowa State University in 1976 also included statictesting on eyebars. In this testing, seventeen undamaged specimens and three damagedand repaired specimens were tested. Of these eyebars, none failed in the eye and allfailed either in the shank of the eyebar or at an original forging (Elleby, 1976).Therefore, for the statically tested specimens, the eye connections of the eyebars areadequate but the forgings in the eyebars need to also be checked for cracking.Charpy impact testing of historic wrought iron was also completed in the presentstudy to determine the fracture toughness of the material. Charpy impact specimens weremachined from eyebars in different orientations simulating crack growth in differentdirection along the eyebar. It was determined that the fracture toughness of wrought ironvaries according to the direction of crack growth in the material.