Probing the Residual Stresses of the Arecibo Telescope Cable Anchors - A Forensic Study

Major civil infrastructure systems face a multitude of hazards in their decades to centuries of service. Understanding the internal mechanics of critical members in such structures under fracture, embrittlement, corrosion, and fire is therefore pivotal in their stewardship. An exciting case study is presented with neutron measurements made on post-failure samples to support the forensic investigation of the Arecibo Telescope collapse in Puerto Rico. We specifically present a recent array of neutron experiments performed at the MARS and SNAP neutron imaging and the HIDRA residual stress instruments. We prove, through residual stress measurements on post-failure socket specimens, the post-failure stress configuration and, in extension, the mode of failure of the structure. We conclude with a look to emerging neutron characterization techniques in engineering materials and beyond relevant to the residual stress field.