Benedikt Engel

University of Nottingham | Notts · Department of Mechanical, Materials and Manufacturing Engineering

Polycrystalline nickel-based superalloys tend to have large grains within component areas where high loads are dominant during operation. Due to these large grains, caused by the manufacturing and cooling process, the orientation of each grain becomes highly important, since it influences the elastic and plastic behaviour of the material. With the...

This paper describes the project GivEn that develops a novel multicriteria optimization process for gas turbine blades and vanes using modern "adjoint" shape optimization algorithms. Given the many start and shutdown processes of gas power plants in volatile energy grids, besides optimizing gas turbine geometries for efficiency, the durability unde...

The polycrystalline nickel-base superalloy RR1000 is used as turbine rotor material in Rolls-Royce aero engines and has to withstand a wide variety of load and temperature changes during operation. In order to maximize the potential of the material and to improve component design, it is of great interest to understand, and subsequently be able to a...

Two different material batches made of random and textured orientated polycrystalline nickel-base superalloy René80 were investigated under isothermal low cycle fatigue tests at 850 °C for a notched specimen geometry. In contrast to a smooth specimen geometry, no significant improvement in fatigue behaviour of the notched specimen could be observed...

For critical component application, such as aerospace turbine rotors, it is imperative to be able to make accurate in-service material behaviour and component life predictions for both design and monitoring of component life. The development of such predictive capability is dependent on the quality of the experimental data from which the material p...

This paper describes the project GivEn that develops a novel multiobjective optimization process for gas turbine blades and vanes using modern “adjoint” shape optimization algorithms. Given the many start and shut-down processes of gas power plants in volatile energy grids, besides optimizing gas turbine geometries for efficiency, the durability un...

The current paper presents work on identification and evaluation of a range of factors influencing accuracy and comparability of data generated by three laboratories carrying out stress-controlled thermo-mechanical fatigue crack growth tests. It addresses crack length measurements, heating methods and temperature measurement techniques. It also pro...

An understanding of rate dependency over a wide range of time scales is vitally important in approximating the transient response of critical components operating in extreme environments. Many examples of viscoplastic model formulations can be found in the literature, wherein all rate dependency is assumed to occur after yielding. Such models negle...

The current paper describes TMF crack growth behaviour in an advanced nickel-based superalloy. Changes in behaviour are examined which occur as a function of the phase angle between applied stress and temperature. The fractography of the failed specimens reveals changes from transgranular to intergranular growth between high and low phase angle tes...

This paper describes the project GivEn that develops a novel multicriteria optimization process for gas turbine blades and vanes using modern "adjoint" shape optimization algorithms. Given the many start and shut-down processes of gas power plants in volatile energy grids, besides optimizing gas turbine geometries for efficiency, the durability und...

New probabilistic lifetime approaches for coarse grained Ni-base superalloys supplement current deterministic gas turbine component design philosophies; in order to reduce safety factors and push design limits. The models are based on statistical distributions of parameters, which determine the fatigue behavior under high temperature conditions. In...

Ein detailliertes Verständnis des Ermüdungs- und Verformungsverhalten von polykristallinen Nickelbasis Superlegierungen, welche für Turbinenschaufeln im Heißgasstrom von Gasturbinen verwendet werden, ist sowohl aus wirtschaftlichen Aspekten als auch zur Erhöhung des Wirkungsgrads von entscheidender Bedeutung. Durch die Fertigung als Gussbauteil ent...

Ein detailliertes Verständnis des Ermüdungs- und Verformungsverhalten von polykristallinen Nickelbasis Superlegierungen, welche für Turbinenschaufeln im Heißgasstrom von Gasturbinen verwendet werden, ist sowohl in wirtschaftlicher Hinsicht als auch zur Erhöhung des Wirkungsgrads von entscheidender Bedeutung. Durch die ertigung als Gussbauteil entst...

In the present work, theoretical approaches, based on grain orientation dependent Young's modulus and Schmid factor are used to describe the influence of local grain orientation on crack initiation behaviour of the coarse grained nickel base superalloy Ren\'e80. Especially for strongly anisotropic crystal structures with large grain size, such as t...

Fluctuating loads in gas turbine power plants result in considerable thermal and mechanical stress in turbine blades. For further improve efficiency by utilizing fatigue strength of Ni-base superalloys to its limits, the high temperature fatigue behaviour of the representatively chosen René80 alloy is investigated with focus on microstructural proc...

In the present work, theoretical approaches, based on grain orientation dependent Young’s modulus and Schmid factor are used to describe the influence of local grain orientation on crack initiation behaviour of the coarse grained nickel base superalloy René80. Especially for strongly anisotropic crystal structures with large grain size, such as the...