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Manukau City, New Zealand

Chen L.,Heavy Engineering Research Association | Chen J.,Beihang University
Chinese Journal of Aeronautics | Year: 2015

A first study on the continuous adjoint formulation for aerodynamic optimization design of high pressure turbines based on S2 surface governed by the Euler equations with source terms is presented. The objective function is defined as an integral function along the boundaries, and the adjoint equations and the boundary conditions are derived by introducing the adjoint variable vectors. The gradient expression of the objective function then includes only the terms related to physical shape variations. The numerical solution of the adjoint equation is conducted by a finite-difference method with the Jameson spatial scheme employing the first and the third order dissipative fluxes. A gradient-based aerodynamic optimization system is established by integrating the blade stagger angles, the stacking lines and the passage perturbation parameterization with the quasi-Newton method of Broyden-Fletcher-Goldfarb-Shanno (BFGS). The application of the continuous adjoint method is validated through a single stage high pressure turbine optimization case. The adiabatic efficiency increases from 0.8875 to 0.8931, whilst the mass flow rate and the pressure ratio remain almost unchanged. The optimization design is shown to reduce the passage vortex loss as well as the mixing loss due to the cooling air injection. © 2015 The Authors. Source

Hicks S.,Heavy Engineering Research Association | Uy B.,University of New South Wales
Engineering for Progress, Nature and People | Year: 2014

This paper presents some of the innovations that will be included within the new joint Australian and New Zealand Bridge Design Standard for Steel and Composite Construction AS/NZS 5100.6, which will be the first harmonized standard between Australia and New Zealand for the design of bridges. As Chairs of the Committees responsible for AS/NZS 5100.6 and AS/NZS 2327, the authors of this paper present the challenges faced from the introduction concrete compressive strengths up to 100 MPa and quenched and tempered steels with a yield strength up to 690 MPa. Perhaps one of the most innovative aspects of this standard is the introduction of an appendix that provides conformity assessment requirements for steel products that are not sourced from either Australia or New Zealand. This appendix is underpinned by rigorous structural reliability analyses undertaken by Australian and New Zealand researchers, which included the present authors of this paper. Source

Hicks S.,Heavy Engineering Research Association | Uy B.,University of New South Wales | Kang W.-H.,University of Western Sydney
IABSE Conference, Geneva 2015: Structural Engineering: Providing Solutions to Global Challenges - Report | Year: 2015

In 2010 the structural Eurocodes replaced the equivalent national standards in all EU member states. As a result of this, many other countries around the world that have historical connections with the UK are now adopting the Eurocodes as their national standards. For steel construction, adoption is proving challenging in these countries. This paper describes the different approaches that are being used in the Asia-Pacific region. Source

Kang W.-H.,University of Western Sydney | Hicks S.,Heavy Engineering Research Association | Uy B.,University of New South Wales
Australian Journal of Structural Engineering | Year: 2015

The performance of the design equations given in the Australian Bridge and Steel Standards AS 5100.6 and AS 4100 have been evaluated when structural steel is used that conforms with the tolerances within the following overseas manufacturing standards: EN 10034, KS D 3502, JIS F 3192, JIS A 5526, ASTM A6/A6M-07 and AS/NZS 5100.6. From a consideration of the experimental results from full-scale bending tests, reliability analyses according to AS 5104: 2005/ISO 2394:1998 and EN 1990 were conducted. From these analyses, a capacity factor of between 0.93 and 0.95 was determined for beams that have compact, not-compact and non-compact cross-sections when a target reliability index of 3.04 was used, based on the standardised FORM (fi rst order reliability method) sensitivity factor for resistance given in AS 5104: 2005/ISO 2394:1998. This fi nding demonstrates that the capacity factor of 0.90 given in AS 4100 and AS 5100.6 for beams in bending is on the conservative side for steel sections complying with overseas manufacturing standards, and supports the design practice that has been adopted in NZS 3404.1 for the last 35 years. © Institution of Engineers Australia, 2015. Source

Thai H.-T.,University of New South Wales | Thai H.-T.,La Trobe University | Uy B.,University of New South Wales | Kang W.-H.,University of Western Sydney | Hicks S.,Heavy Engineering Research Association
Journal of Constructional Steel Research | Year: 2016

This paper presents an accurate and efficient numerical procedure for evaluating the system reliability of steel frames with semi-rigid connections. The ultimate strength and behaviour of the frame were predicted using a refined plastic hinge model due to its computational efficiency, whilst the nonlinear behaviour of semi-rigid connections was captured using a three-parameter power model. The statistical properties for the three parameter power model were obtained based on available experimental results. The sensitivity of reliability to the model error was also studied. Monte Carlo simulation was used to estimate the probability of failure and the reliability index of a system. Two example frames subjected to combined gravity and wind loads were examined and their system reliability indices for both strength and serviceability limit states were evaluated based on the randomness in loadings, material and geometric properties and semi-rigid connections. The results indicate that the frame reliability is strongly affected by semi-rigid connections. © 2016 Elsevier Ltd. All rights reserved. Source

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