Predicting the cutting rate of a dimamond wire

Abstract

The process of salvaging wrecks can be costly and time-consuming, making it crucial for salvagers to select the appropriate technique(s) and accurately estimate the total costs to minimize expenses and optimize efficiency. Salvagers typically use their expertise, experience, and data from previous projects to make these estimates. Diamond wire cutting is a material-cutting technique with much potential for use in wreck salvaging. However, a previously conducted literature review revealed a lack of sufficient information in the existing literature to determine the cutting rates of diamond wire used in wreck removal, indicating a gap in current knowledge. A deeper understanding of the technique is needed to evaluate salvagers' capability of cutting diamond wire in wreck removal. Therefore, the primary focus of this paper is to provide a method to estimate the cutting rate of diamond wire when used in wreck removal. The effect of wire speed, normal load on the workpiece, various materials encountered in wreck cutting, different geometries, and environments on cutting rate have been investigated. Filling this knowledge gap is of particular interest to Boskalis, as they currently have limited knowledge and experience with diamond wire cutting, making it challenging to estimate costs. Additionally, research into wreck removal techniques is socially significant, as the ability to remove wrecks efficiently and with minimal environmental impact is crucial. Therefore, this thesis aims to provide a deeper understanding of diamond wire cutting in its application in wreck removal.


Main factors determining the potential of a technique for removal include the total duration of removal, the required assets, and the associated risks. The primary focus of this thesis is to develop a method to estimate the cutting rate of diamond wire when used in wreck removal. The cutting rate will be predicted using the Archard wear equation, which requires an unknown coefficient ($K$) that can be determined through experiments. A real-world set-up with diamond wire was used to obtain data.

The results show that for the steels and cast iron in this survey, Archard's assumption that the wear volume is inversely proportional to hardness is not supported. Consistent with Archard’s equations, the wear volume has been found to be proportional to normal load, sliding distance but independent of speed within the range of tested conditions. As such, the Archard wear equation can be applied to the materials tested, but its applicability to materials that differ significantly from those tested is uncertain. Furthermore, results show that cooling significantly impacts both wire life and cutting rate. Specifically, fully submerging the workpiece resulted in a
XX\% improvement in the cutting rate as compared to spraying with coolant. It should be noted that these results were obtained under controlled conditions where normal load, wire speed, and cutting angle were kept constant, and proper cooling was possible. These operational parameters may vary in real-world scenarios, such as cutting through a shipwreck, leading to deviation from the predicted cutting rates.