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This study investigates the effects of shot peening on the low-cycle fatigue performance of a low-pressure steam turbine blade material. The finite element model incorporating shot-peening effects, which has been introduced in part I, has been used to predict the stabilised stress/strain state in shot-peened samples during fatigue loading. The application of this model has been extended to different notched geometries in this study. Based on the modelling results, both the Smith-Watson-Topper and Fatemi-Socie critical plane fatigue criteria have been used to predict the fatigue life of shot-peened samples (treated with two different peening intensities) with varying notched geometries. A good agreement between experiments and predictions was obtained. The application of a critical distance method considering the stress and strain hardening gradients near the shot-peened surface has been found to improve the life prediction results. The effects of surface defects on the accuracy of life predictions using the proposed method were also discussed. [ABSTRACT FROM AUTHOR]

In this study, the residual stress relaxation behaviour occurring during low-cycle fatigue in shot-peened specimens with either a flat or a notched geometry has been studied. A representative low-pressure steam turbine material, FV448, was used. The residual stress and strain hardening profiles caused by shot peening were measured experimentally and were then incorporated into a finite element model. By allowing for both effects of shot peening, the residual stress relaxation behaviour was successfully simulated using this model and correlated well with the experimental data. Although more modelling work may be required to simulate the interaction between shot peening effects and external loads in a range of notched geometries, the model predictions are consistent with the specimens tested in the current study. The novelty of this study lies in the development of such a modelling approach which can be used to effectively simulate the complex interaction between shot peening effects and external loads in notched regions. Compared with the un-notched geometry, the notched geometry was found to be more effective in retaining the improvement in fatigue life resulting from shot peening, by restricting the compressive residual stress relaxation during fatigue loading. [ABSTRACT FROM AUTHOR]

This article reports selected findings from a collaborative research study into the fundamental understanding of laser shock peening (LSP), when applied to key airframe and aero-engine alloys. The analyses developed include explicit simulations of the peening process together with a simpler eigenstrain approach, which may be used to provide an approximation to the residual stress field in a number of geometries. These are chosen to represent parts of structural components under conditions relevant to service applications. The article shows that the eigenstrain approach can provide good approximations to the stress field in most circumstances and may provide a computationally efficient tool for exploring different peening strategies. Both explicit and eigenstrain results demonstrate that the interaction between the LSP process and geometric features is important for understanding the subsequent performance of components. Particularly relevant for engineering applications is that not all instances of LSP application may provide an improvement in structural integrity. [ABSTRACT FROM AUTHOR]

In this paper, a 5 DOF trans-humeral robotic prosthesis: MoBio is proposed. MoBio includes 2 DOF at wrist which is rare in other trans-humeral prostheses. Through anthropometric features MoBio prosthetic arm can achieve elbow flexion/extension, forearm supination/pronation, wrist radial/ulnar deviation, wrist flexion/extension and compound motion of thumb and index finger. An EMG based control method which uses EMG signals of the biceps brachii and triceps brachii, is used with a motion switching mechanism to control the prosthesis. Experimental results have verified the usability and effectiveness of MoBio in performing Activities of Daily Living.