About
30
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Introduction
His main areas of research are process modelling of inertia friction welding for aerospace application and high-temperature structural integrity, focusing on material and structure numerical modelling. Currently, he is investigating new remeshing scheme for IFW and material modelling for nickel superalloys. During his Ph.D. and past research, he investigated the effects of high-temperature creep and fatigue on the crack initiation process in metallic structures. He also has other areas of interest such as advanced materials and space deployable structures.
Current institution
Additional affiliations
August 2017 - present
October 2016 - July 2017
August 2010 - September 2013
Position
- Student Trainee
Description
- Structural analysis of ultra thin composite deployable structures, and thin tensioned membranes behavior. Fabrication study and electrical characterization of epoxy nanocomposite. Catalist and carbon nanotubes in-situ growth by CVD.
Education
October 2010 - July 2013
September 2006 - June 2010
Publications
Publications (30)
Metal Matrix Composite (MMC) represents a valuable option as structural material for different type of structures and components. Despite this they struggle to become widely adopted due to expensive manufacturing process and complex microstructural behaviour. When subjected to cyclic load conditions the structural response of MMC is not trivial, an...
As the energy demand increases the power industry has to enhance both efficiency and environmental sustainability of power plants by increasing the operating temperature. The accurate creep fatigue life assessment is important for the safe operation and design of current and future power plant stations. This paper proposes a practical creep fatigue...
In this paper, the extended Direct Steady Cyclic Analysis method (eDSCA) within the Linear Matching Method Framework (LMMF) is combined with the Stress Modified Ductility Exhaustion method and the modified Cavity Growth Factor (CGF) for the first time. This new procedure is used to systematically investigate the effect of several load parameters in...
This study details the development and validation of a finite element methodology to robustly simulate the inertia friction welding (IFW) process. There are many difficulties involved in modelling IFW. These include the short and violent process to complete a weld, as well as the challenges in obtaining experimental data throughout the process to c...
Motivated by the inability of classical computational plasticity to fully exploit modern scientific computing, a multifield formulation for finite strain plasticity is presented. This avoids a local integration of the elastoplastic model. In the multifield approach, the balance of linear momentum, the flow relation and the Karush–Kuhn–Tucker constr...
For the preservation of painted cultural heritage on wooden substrates, it is important to understand the fracture mechanisms in the multilayer system of which they are constructed and how the environment plays a role in the composites’ physical properties. Past research has investigated the material response of each constituent layer but much more...
Life integrity assessment of industrial components often requires investigations of the cyclic inelastic response at a range of operating temperatures. Some high strength steels exhibit a well-known ambient temperature creep behaviour, which can also impact the cyclic behaviour, especially under long-term operation. In this study, a direct method k...
Structural integrity plays an important role in any industrial activity, due to its capability of assessing complex systems against sudden and unpredicted failures. The work here presented investigates an unexpected new mechanism occurring in structures subjected to monotonic and cyclic loading at high temperature creep condition. An unexpected acc...
Most industrial structures are affected by material mismatch effects, due to the design necessity that leads to the use of dissimilar materials like welding of different parts. In other circumstances, this mismatch is introduced by material transformation like radiation embrittlement, hydrogen attack or carburisation, which can drastically change t...
The preliminary design of the international space mission HECATE (Human Exploration of Cis-lunar space via Assets Tele-operated from EML2) is briefly discussed. HECATE aims at exploring the far side of the Moon via tele-robotic activities during the 2020s and with the objective to establish human presence in cis-lunar space, following the current v...
An aluminium (Al, 2024T3) matrix composite reinforced with continuous alumina (Al2O3) fibres is investigated under tensile off-axis constant macro stress and thermal cyclic loading. The micromechanical approach to modelling and three different fibre cross-section geometries have been employed. The effect of creep is included by considering three dw...
Ratcheting and low cycle fatigue are failure mechanisms observed in components subjected to cyclic temperature and mechanical loads. Ratcheting is a global failure mechanism which leads to an incremental plastic collapse of the component whereas low cycle fatigue is a localized mechanism which leads to crack initiation. It is exacerbated by grooves...
This paper introduces the latest research and development of the Linear Matching Method (LMM) on the creep fatigue damage assessment of components subjected to high temperature and cyclic load conditions. The method varies from existing rule-based approaches in both the ASME Boiler and Pressure Vessel Code (NH) and the UK R5 high temperature assess...
The LMM subroutines and plug-in tools for structural integrity assessment are now in extensive use in industries for the design and routine assessment of power plant components. This paper presents a detailed review and case study of the current state-of-the art LMM direct methods applied to the structural integrity assessment. The focus is on the...
This paper presents the preliminary design of
the international space mission HECATE (Human
Exploration of Cis-lunar space via Assets
Tele-operated from EML-2), aimed at exploring
the far side of the Moon via telerobotic
activities during the 2020s. The exploration
is realized by astronauts from HOPE
(Human Orbiting Protected Environment), a
space...
This paper investigates the cyclic plastic behavior of continuous fiber-reinforced aluminum matrix composites (CFAMCs) with different shape of fiber cross section arranged in a square packing geometry. The 2D micromechanical FEM models, composed of elastic undamaged reinforcement perfectly bonded to an elastic-perfectly plastic matrix with a volume...
The Linear Matching Method Framework (LMMF) consists of a number of simplified direct methods for generating approximate inelastic solutions and answering specific design related issues in pressure vessel design codes using standard finite element codes. Currently, all the LMM procedures have been implemented in ABAQUS through user subroutines with...
The mechanical behaviour of Metal Matrix Composites (MMCs) subjected to a high temperature and cyclic load condition is difficult to understand. The significantly differing coefficients of thermal expansion between ceramic and metal give rise to micro thermal stresses. Their performance under varying load and high temperature is complex and inconsi...
This poster presents the preliminary design of the international space mission HECATE (Human Exploration of Cis-lunar space via Assets Tele-operated from EML-2), aimed at exploring the far side of the Moon via tele-robotic activities during the 2020s. The mission will deliver a habitat (HOPE, Human Orbiting Protected Environment) in cis-lunar space...
The accurate assessment of creep fatigue interaction is an important issue for industrial components operating with large cyclic thermal and mechanical loading. This paper proposes a comprehensive overview of the important behaviours that limit the life of components, including cyclically enhanced creep, creep enhanced plasticity and creep ratchett...
The main purpose of this work is to present the results obtained by the Structural Design and Life Assessment Research Group on the plastic and creep structural response of Metal Matrix Composite (MMC) using the Linear Matching Method (LMM). Throughout the literature different approaches for modelling fibre or particles reinforced aluminium alloy M...
![Out-plane displacement for 0.6 N and 18 N tensioning load [m].](publication/280611861/figure/fig4/AS:1088551672393752@1636542351753/Out-plane-displacement-for-06N-and-18N-tensioning-load-m_Q320.jpg)
Typical square solar-sail design is characterised by a central hub with four-quadrant sails, conferring to the spacecraft the classical X-configuration. One of the critical aspects related to this architecture is due to the large deformations of both membrane and booms, which leads to a reduction of the performance of the sailcraft in terms of thru...
The accurate assessment of creep rupture limit is an important issue for industrial components under combined action of cyclic thermal and mechanical loading. This paper proposes a new creep rupture assessment method under the Linear Matching Method framework, where the creep rupture limit is evaluated through an extended shakedown analysis using t...
In this work we investigated the stability behavior and the folding capability of an ultrathin tubular composite boom with C-cross section to be used in nanosatellites applications. A nonlinear buckling analysis was performed using the Riks method, adopting a perturbed finite element model to study the influence of the unavoidable geometrical varia...
Nowadays the interest in nano-satellites and microsatellites is rapidly growing, and with that the design of thinner and stiffer booms becomes an emerging topic. Satellites and deep space probes often need long structures to keep instrumentations far from other satellite components or simply to stabilize low orbit spacecrafts via gravity gradient....
Questions
Questions (8)
Dear all,
I am developing and deubugging a UMAT visco elastic subroutine. I corrected most of the bugs related to it, but I am finding a bit difficult to correct the following issue. This routine requires a trial stress to be used to initiate an iterative solving process. My issue is that at the start this is zero and if I do not provide any stress this would not solve anything since after first increment, with everything to zero, the next one will have lot of zero divisions and this is not admissible.
Do you have any advice on how to deal with this issue? Maybe I am missing something really fundamental?
Thank you in advance.
Dear all,
I have realised a framework of Fortran subroutines and python ( for subsequent model generation from deformed shape and mapping solution) scripts to perform a complex simulation that involves the use of *FRIC, *UEL, *UHARD and *USDFLD, plus several python scripts. Results obtained so far are excellent and match neatly experiment. However, since I started to use more than 1 core I started to have, in a random way, a fatal error during the remeshing and solution mapping. I say this because I got a the error while operating pre.exe and because the .dat file is truncated just before starting the solution mapping starts. I am trying different things but nothing seems to help. In addition, I am quite confident this is due to cores number because when I use a single core I can solve the simulation. The error message is here below if you have any idea I am happy to try.
Thank you!
ERROR: file: G:\R419\BSF\SMABase\SMABasOmni.m\src\omn_CrashHandler.cpp line: 588*** Error: pre.exe / rank 0 / thread 0 encounted an EXCEPTION_ACCESS_VIOLATION (code 3221225477)(null)
ABQSMAIomCore.dll admC_File::CheckOut
ABQSMAAncAdbModule.dll adb_File::GetMetadata
ABQSMAAncAdbModule.dll adb_File::RetrievePackage
ABQSMAAncAdbModule.dll adb_BytePackage::adb_BytePackage
ABQSMAAncAdbModule.dll adb_GPackage::adb_GPackage
ABQSMAAncAdbModule.dll adb_FramePackage::RebootFrameRetrieve
ABQSMAAncAdbModule.dll adb_FramePackageHandler::RetrieveFrame1
ABQSMAAncAdbModule.dll adb_FramePackageHandler::RetrieveFrame
ABQSMAStsMapSoln.dll map_Model_odb::map_Model_odb
ABQSMAPreCore.dll mapstate
ABQSMAPreCore.dll pre
ABQSMAPreCore.dll pre_main
pre.exe ???
pre.exe ???
pre.exe BasicLicenser::EndLongTransaction
KERNEL32.DLL BaseThreadInitThunk
ntdll.dll RtlUserThreadStart
31/01/2019 21:29:53
Abaqus Error: The executable pre.exe
aborted with system error code 1073741819.
Please check the .dat, .msg, and .sta files for error messages if the files
exist. If there are no error messages and you cannot resolve the problem,
please run the command "abaqus job=support information=support" to report and
save your system information. Use the same command to run Abaqus that you
used when the problem occurred. Please contact your local Abaqus support
office and send them the input file, the file support.log which you just
created, the executable name, and the error code.
Dear all,
I am a nearly 8 year Abaqus user, and I never see this happening.
Essentially I am scripting a UMAT in Abaqus 6.17 and I have done this exact same scripting in Abaqus 6.12.3 without any issue.
When I read the results from the odb, the simulation is properly completed, all SDV are computed but once I scroll down to see over sdv 11 at sdv12 it returns to sdv1. Now the issue is that if I try to output the values of sdv12 at any element they are there! So this mean the subroutine is working, and results are correct. However, I cannot see these on the contour and wont let me plot the sdv12 contour. This happen also for other sdvs like sdv 201 etc. If I start to scroll the sdvs from sdv 13 it will show the contour but again it will fail at some point. Does anyone had similar experience? I have the fear some bugs in Abaqus 6.17.
Many thanks for any tip!
Dear all,
I am facing some difficulties with this last release, and I would like to ask few question to some users who are using the 2017.
1. I would like to set up the proper ABA_ACCELERATOR_TYPE to use the GPGPU acceleration. As suggested by the Monitor and by the documentation I went in the proper folder "solvers_install_dir/os/SMA/site/ " to find out the abaqus_v6.env file. Well it is not there! Do you have the same issue? Probably I will ask to the IT to re-install again it but to me is not normal to have this file missing.
2. Do you mind to share with me your abaqs_v6.env file? In this case I can check how it looks like and maybe I can avoid to re-install everything.
3. Did someone tested the GPGPU acceleration? How does it works in terms of acceleration? Which GPU you consider the best compromise between cost and computational acceleration?
Thank you all for your replies,
Kind regards
Daniele
