Juan Felipe Beltrán

Numerical Simulation of Damage Localization in Polyester Mooring Ropes

This paper presents the derivation of a mechanical model to estimate the effects of damage on the response of ropes. Damage can be represented through a degradation of the properties of individual rope elements, and it can also include the complete rupture of one or more elements. The general assumptions made to estimate the length over which damage propagates along the length of a rope and how this length is considered in modeling damaged rope behavior are explained. Consistent with tests on damaged polyester (PET) mooring ropes, numerical simulations demonstrate the existence of strain localization around the failure region and, due to degradation of rope element properties, damage localization as well. This damage localization causes the premature failure of rope elements, reducing the maximum load capacity and maximum failure strain that a damaged rope is capable of resisting relative to that of an intact rope. The proposed model suggests that some of the variables that affect damaged rope behavior are the degree of damage present at a given cross-section, the location of broken rope elements, and the length over which damage propagates along the rope length. Experimental data are used to validate the model.

Analysis of a simple displacement sensor based on BOTDR optical fiber

A monitoring system based on a PVC tube instrumented with optical fiber connected to a Brillouin Optical Time Domain Reflectometer (BOTDR) apparatus is studied to estimate slope movement. A series of displacement tests were performed on 4 and 5m long PVC tubes with 40 and 25 mm diameter using optical fiber along their external surfaces. The PVC tubes are subjected to controlled displacements on 4 contact points of the PVC to replicate the possible response of soil mass during slope failure or displacement. The response of this system is described through measurements of axial displacements on the PVC tube using BOTDR optical fiber, strain gages and theoretical estimates based on strength of materials formulae. The experimental findings indicate that the use of optical fiber is adequate to obtain the axial deformation of the tube and to estimate the displacements at the contact points (back-analysis).

Reconnaissance Report of Chilean Industrial Facilities Affected by the 2010 Chile Offshore Bío-Bío Earthquake

This paper summarizes findings of an EERI reconnaissance team and a group of Chilean experts on damage to industrial facilities caused by the 27 February 2010 Offshore Bío-Bío Earthquake and ensuing tsunami. Chiles industry as a whole was severely affected when major industrial plants such as paper mills, wood mills, thermoelectric power plants, and oil and gas refineries were shut down following the earthquake either in response to the damage sustained or to maintain structural and environmental safety. Damage resulted primarily from ground shaking; however, it was exacerbated by the ensuing tsunami in coastal areas. Important industrial sectors, such as the wine industry and fishing, pulp and paper industries, suffered severely. Observed damage was primarily due to inadequate anchorage of equipment, differential movements between adjacent supports of piping and equipment, foundation displacements, and failure of non-structural elements and equipment.