Anoop Vasu and Ramana V. Grandhi
The impact of laser peening on curved geometries is not fully comprehended. The purpose of this paper is to explain the action of laser peening on curved components (concave and…
Abstract
Purpose
The impact of laser peening on curved geometries is not fully comprehended. The purpose of this paper is to explain the action of laser peening on curved components (concave and convex shapes for cylindrical and spherical geometries) by means of shock wave mechanics.
Design/methodology/approach
An analytical formulation is derived based on the plasticity incurred inside the material and the results are compared with the prediction by numerical simulation.
Findings
A near-linear relationship is observed between curvature and compressive residual stress; an increasing trend was observed for concave models and a decreasing trend was observed for convex models. The consistency in the analytical formulation with the simulation model indicates the behavior of laser peening for curved geometries.
Originality/value
The differences observed in the residual stresses for spherical and cylindrical geometries are primarily due to the effect of Rayleigh waves. This paper illustrates the importance of understanding the physics behind laser peening of curved geometries.
Details
Keywords
Thomas J. Spradlin, Ramana V. Grandhi and Kristina Langer
The purpose of this paper is to develop and implement a structural fatigue life estimation framework that includes laser‐peened (LP) residual stresses and then experimentally…
Abstract
Purpose
The purpose of this paper is to develop and implement a structural fatigue life estimation framework that includes laser‐peened (LP) residual stresses and then experimentally validates these fatigue life estimations.
Design/methodology/approach
A three‐dimensional finite element analysis of an Al 7075‐O three‐point bending coupon being LP was created and used to estimate the fatigue life when loaded. Fatigue tests were conducted to validate these estimations.
Findings
The framework developed for fatigue life estimation of LP‐processed coupons yielded estimates with goodness‐of‐fit between the log‐transformed experimental and analytical data of R2=0.97 for the baseline coupons and R2=0.94 for the LP‐processed coupons.
Research limitations/implications
Approximated ε‐life fatigue parameters were used to calculate the fatigue life resulting from the complex residual stress fields due to the simulated LP process.
Originality/value
A fatigue life estimation framework that considers LP residual stress fields has been developed for use on structural components.
Details
Keywords
Harvinder Singh, Rashmi Kumar Aggarwal and Aakriti Bansal
The learning outcome of this paper is to understand the geopolitical aspects of international business. Assessing the political risk inherent in international investment projects…
Abstract
Learning outcomes
The learning outcome of this paper is to understand the geopolitical aspects of international business. Assessing the political risk inherent in international investment projects. Maintaining a favorable corporate image in the host country despite apparent hostilities. Analyzing the risks associated with doing business in an emerging market.
Case overview/synopsis
In February 2019, local newspapers in the Maldives published unconfirmed reports that the Indian company GMR was reinvesting in the Maldives. GMR had secured a contract in 2010 for renovation/expansion of The Maldives International Airport. However, the contract created political turmoil, with opposition parties objecting to some clauses. People considered GMR closer to the incumbent President, Mohammed Nasheed. The unstable political scenario forced President Nasheed to resign amidst allegations of corruption. The new President showed hostility toward India and GMR while making overtures to China. He canceled the airport contract and awarded it to a Chinese company. GMR went to the international Tribunal in Singapore. The tribunal upheld the Maldivian government’s right to terminate the agreement but awarded GMR a compensation of US$270m. In 2019, a new government came to power in the Maldives, with Mohammed Nasheed enjoying a commanding position. The government pledged to accept the judgment of the Singapore International Tribunal. The local media discussed the possibility of the return of GMR to the Maldives after seeing some senior GMR officials in the Maldives. However, it was not clear whether it would be a good idea for GMR.
Complexity academic level
Master's level program.
Supplementary materials
Teaching notes are available for educators only.
Subject code
CCS 11: Strategy.