Change search
Link to record
Permanent link

Direct link
BETA
Kokkolaras, Michael
Publications (10 of 90) Show all publications
Hoffenson, S., Arepally, S., Kokkolaras, M. & Papalambros, P. (2013). Quantification of the design relationship between ground vehicle weight and occupant safety under blast loading (ed.). Paper presented at . International Journal of Vehicle Design, 61(1/2/3/4), 204-218
Open this publication in new window or tab >>Quantification of the design relationship between ground vehicle weight and occupant safety under blast loading
2013 (English)In: International Journal of Vehicle Design, ISSN 0143-3369, E-ISSN 1741-5314, Vol. 61, no 1/2/3/4, p. 204-218Article in journal (Refereed) Published
Abstract [en]

Military ground vehicle design must consider the threat posed by underbody blasts to new vehicles and their occupants, while also accounting for weight reduction goals for improving fuel economy and mobility. A two-stage process is presented to model the blast event, using LS-DYNA for simulating vehicle response and MADYMO for the occupant's response. Issues including computational expense, objective function formulation and multi-objective seating system design optimisation are addressed in detail, and three different blastworthiness optimisation formulations are presented and evaluated

National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:ltu:diva-9561 (URN)10.1504/IJVD.2013.050846 (DOI)835c1b91-5b70-45a6-87d3-de8aa4a100fc (Local ID)835c1b91-5b70-45a6-87d3-de8aa4a100fc (Archive number)835c1b91-5b70-45a6-87d3-de8aa4a100fc (OAI)
Note
Upprättat; 2013; 20110318 (marsan)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Kokkolaras, M., Hulbert, G., Papalambros, P., Mourelatos, Z., Yang, R.-J., Brudnak, M. & Gorsich, D. (2013). Towards a comprehensive framework for simulation-based vehicle systems design validation (ed.). Paper presented at . International Journal of Vehicle Design, 61(.1/2/3/4), 233-248
Open this publication in new window or tab >>Towards a comprehensive framework for simulation-based vehicle systems design validation
Show others...
2013 (English)In: International Journal of Vehicle Design, ISSN 0143-3369, E-ISSN 1741-5314, Vol. 61, no .1/2/3/4, p. 233-248Article in journal (Refereed) Published
Abstract [en]

We present an overview of our most recent and ongoing research efforts to develop a comprehensive framework for simulation-based design validation of vehicle systems. Specifically, we present the three major building blocks of our framework: (1) the introduction of an appropriate validation metric for dealing with the multivariate functional data that are the output of dynamic vehicle systems; (2) the robust implementation of a Bayesian interval-based hypothesis testing technique for quantifying the confidence in simulation models used for design under uncertainty; (3) the development of a sequential design optimisation and calibration-based validation methodology that addresses the inadequacy of current validation practices in simulation-based design optimisation. We present a simple yet illustrative example and discuss the techniques being developed currently that will complete the proposed framework

National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:ltu:diva-12456 (URN)10.1504/IJVD.2013.050847 (DOI)b9c15fe4-ad86-4bff-87eb-ec35247916ee (Local ID)b9c15fe4-ad86-4bff-87eb-ec35247916ee (Archive number)b9c15fe4-ad86-4bff-87eb-ec35247916ee (OAI)
Note
Upprättat; 2013; 20110318 (marsan)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Hu, J., Klinich, K. D., Reed, M. P., Kokkolaras, M. & Rupp, J. D. (2012). Development and validation of a modified hybrid-III six-year-old dummy model for simulating submarining in motor-vehicle crashes (ed.). Paper presented at . Medical Engineering and Physics, 34(5), 541-551
Open this publication in new window or tab >>Development and validation of a modified hybrid-III six-year-old dummy model for simulating submarining in motor-vehicle crashes
Show others...
2012 (English)In: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 34, no 5, p. 541-551Article in journal (Refereed) Published
Abstract [en]

In motor-vehicle crashes, young school-aged children restrained by vehicle seat belt systems often suffer from abdominal injuries due to submarining. However, the current anthropomorphic test device, so-called “crash dummy”, is not adequate for proper simulation of submarining. In this study, a modified Hybrid-III six-year-old dummy model capable of simulating and predicting submarining was developed using MADYMO (TNO Automotive Safety Solutions). The model incorporated improved pelvis and abdomen geometry and properties previously tested in a modified physical dummy. The model was calibrated and validated against four sled tests under two test conditions with and without submarining using a multi-objective optimization method. A sensitivity analysis using this validated child dummy model showed that dummy knee excursion, torso rotation angle, and the difference between head and knee excursions were good predictors for submarining status. It was also shown that restraint system design variables, such as lap belt angle, D-ring height, and seat coefficient of friction (COF), may have opposite effects on head and abdomen injury risks; therefore child dummies and dummy models capable of simulating submarining are crucial for future restraint system design optimization for young school-aged children

National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:ltu:diva-2997 (URN)10.1016/j.medengphy.2011.08.013 (DOI)0bebb114-7833-4f15-9beb-2fd845e11027 (Local ID)0bebb114-7833-4f15-9beb-2fd845e11027 (Archive number)0bebb114-7833-4f15-9beb-2fd845e11027 (OAI)
Note
Upprättat; 2012; 20110318 (marsan)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Tyapin, I., Sandberg, M., Kokkolaras, M., Lundbladh, A. & Isaksson, O. (2012). Jet engine design optimization using knowledge-based master models (ed.). In: (Ed.), (Ed.), Proccedings of ASME Turbo Expo 2012: . Paper presented at ASME Turbo Expo : 11/06/2012 - 15/06/2012 (pp. 41-47). : American Society of Mechanical Engineers, 7, A and B
Open this publication in new window or tab >>Jet engine design optimization using knowledge-based master models
Show others...
2012 (English)In: Proccedings of ASME Turbo Expo 2012, American Society of Mechanical Engineers , 2012, Vol. 7, A and B, p. 41-47Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a preliminary design optimization study of a jet engine structure using a knowledge-based master modeling approach. The objective function is derived based on input-output relationships of a cost-performance model, where specific fuel consumption, pressure loss and direct cost are considered. The advantage of this problem formulation is that it entails a single composite objective function that takes into account mass, structural characteristics, dynamic response and translates them to a direct operational cost function to be minimized. A fan-blade-off scenario is considered as the loading case in this paper. The loss of one fan blade during nominal operation causes a rotor imbalance and structural deformation.

Place, publisher, year, edition, pages
American Society of Mechanical Engineers, 2012
National Category
Other Engineering and Technologies not elsewhere specified
Research subject
Product Innovation
Identifiers
urn:nbn:se:ltu:diva-27965 (URN)10.1115/GT2012-69309 (DOI)2-s2.0-84881136775 (Scopus ID)1970f7d3-0874-4112-afb8-f73c36fb55a4 (Local ID)978-0-7918-4473-1 (ISBN)1970f7d3-0874-4112-afb8-f73c36fb55a4 (Archive number)1970f7d3-0874-4112-afb8-f73c36fb55a4 (OAI)
Conference
ASME Turbo Expo : 11/06/2012 - 15/06/2012
Note
Godkänd; 2012; Bibliografisk uppgift: Paper no GT2012-69309; 20111122 (marsan)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Cervantes, M., Cupillard, S., Bance, K. & Kokkolaras, M. (2012). Shape optimization of a 3D slider with dimples (ed.). Paper presented at . Journal of Civil Engineering and Architecture, 6(12), 1599-1607
Open this publication in new window or tab >>Shape optimization of a 3D slider with dimples
2012 (English)In: Journal of Civil Engineering and Architecture, ISSN 1934-7359, E-ISSN 1934-7367, Vol. 6, no 12, p. 1599-1607Article in journal (Refereed) Published
Abstract [en]

Sliding contacts in laminar flow regimes have been investigated extensively in recent years. The results indicate the possibility to increase load carrying capacity in a slider bearing for more than 10% with the addition of dimples. Parametric studies have been performed to determine optimal size and position, with emphasis in the optimal shape and position of the dimple for an operating condition. In this article, the numerical analysis of a 2D textured slider bearing with a dimple is initially considered with an isothermal laminar fluid. Position, depth, width and convergence ratio are optimized, the results demonstrate the importance of the width and convergence ratio to increase load. Then, the numerical analysis of a 3D textured slider bearing with fore-region and extended channels at the outlet and on the sides of a pad is considered. The simulations are also carried out for a laminar isothermal flow. Three dimples are considered and their depth is optimized.

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-4361 (URN)24cd5e8d-37e5-4547-b318-7d4588bc8172 (Local ID)24cd5e8d-37e5-4547-b318-7d4588bc8172 (Archive number)24cd5e8d-37e5-4547-b318-7d4588bc8172 (OAI)
Note
Validerad; 2013; 20130411 (cervante)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Isaksson, O., Larsson, T., Kokkolaras, M. & Bertoni, M. (2012). Simulation driven design for product-service systems (ed.). In: (Ed.), Yoshiki Shimomura; Koji Kimita (Ed.), The Philosopher's Stone for Sustainability: Proceedings of the 4th CIRP International Conference on Industrial Product-Service Systems, Tokyo, Japan, November 8th-9th, 2012. Paper presented at CIRP International Conference on Industrial Product Service Systems : 08/11/2012 - 09/11/2012 (pp. 465-470). Berlin Heidelberg: Encyclopedia of Global Archaeology/Springer Verlag
Open this publication in new window or tab >>Simulation driven design for product-service systems
2012 (English)In: The Philosopher's Stone for Sustainability: Proceedings of the 4th CIRP International Conference on Industrial Product-Service Systems, Tokyo, Japan, November 8th-9th, 2012 / [ed] Yoshiki Shimomura; Koji Kimita, Berlin Heidelberg: Encyclopedia of Global Archaeology/Springer Verlag, 2012, p. 465-470Conference paper, Published paper (Refereed)
Abstract [en]

Total Offers, Functional Products, and Integrated Product Service Engineering reflect a shift toward service offers from manufacturing industry captured within the term Product-Service Systems (PSS). Manufacturing companies have traditionally focused design and development activities on realizing technical and engineered aspects of physical artifacts, while PSS include deeper understanding of customers’ expectation, needs and perceived value, hence calling for modelling of additional aspects. The change in early design processes and the effects on virtual modelling of product properties are discussed in this paper through aerospace industry examples to clarify ‘parameters of change’, giving suggestions for a simulation driven design (SDD) approach.

Place, publisher, year, edition, pages
Berlin Heidelberg: Encyclopedia of Global Archaeology/Springer Verlag, 2012
National Category
Other Engineering and Technologies not elsewhere specified
Research subject
Product Innovation
Identifiers
urn:nbn:se:ltu:diva-32160 (URN)10.1007/978-3-642-32847-3_78 (DOI)68eaad33-606e-43cd-a9a4-ab72657ca417 (Local ID)978-3-642-32846-6 (ISBN)978-3-642-32847-3 (ISBN)68eaad33-606e-43cd-a9a4-ab72657ca417 (Archive number)68eaad33-606e-43cd-a9a4-ab72657ca417 (OAI)
Conference
CIRP International Conference on Industrial Product Service Systems : 08/11/2012 - 09/11/2012
Note

Godkänd; 2012; 20120730 (berber)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-05-31Bibliographically approved
Sandberg, M., Tyapin, I., Kokkolaras, M. & Isaksson, O. (2011). A knowledge-based master modeling approach to system analysis and design (ed.). In: (Ed.), Steve Culley; Ben Hicks; Tim McAloone; T.J. Howard (Ed.), Impacting society through engineering design: ICED 11 København, the 18th International Conference on Engineering Design ; 15th - 18th August 2011, Technical University of Denmark (DTU), Copenhagen, Denmark ; proceedings volumes. Paper presented at International Conference on Engineering Design : 15/08/2011 - 19/08/2011 (pp. 347-356). : Design Research Society, 4 : Product and systems design
Open this publication in new window or tab >>A knowledge-based master modeling approach to system analysis and design
2011 (English)In: Impacting society through engineering design: ICED 11 København, the 18th International Conference on Engineering Design ; 15th - 18th August 2011, Technical University of Denmark (DTU), Copenhagen, Denmark ; proceedings volumes / [ed] Steve Culley; Ben Hicks; Tim McAloone; T.J. Howard, Design Research Society, 2011, Vol. 4 : Product and systems design, p. 347-356Conference paper, Published paper (Refereed)
Abstract [en]

The jet engine industry relies on product models for early design predictions of attributes such as structural behavior, mass and cost. When the required analysis models are not linked to the governing product model, effective coordination of design changes is a challenge, making design space exploration time-consuming. Master modeling (MM) approaches can help alleviate such analysis overhead; the MM concept has its origins in the computer-aided design (CAD) community, and mandates that manual changes in one model automatically propagate to assembly, computer-aided manufacturing (CAM) and computer-aided engineering (CAE) models within the CAD platform. Knowledge-based master models can also be used to communicate changes in the product definition to models that are external to the CAD platform. This paper presents details of the knowledge-based master modeling approach as applied to mechanical jet engine analysis and design, where different fidelity models and analysis tools are supported in the early design stages.

Place, publisher, year, edition, pages
Design Research Society, 2011
Series
DS / Design Society ; 68
National Category
Other Engineering and Technologies not elsewhere specified
Research subject
Product Innovation
Identifiers
urn:nbn:se:ltu:diva-38436 (URN)cd69f5a8-be94-44e0-a4b9-cd446848a3aa (Local ID)978-1-904670-24-7 (ISBN)cd69f5a8-be94-44e0-a4b9-cd446848a3aa (Archive number)cd69f5a8-be94-44e0-a4b9-cd446848a3aa (OAI)
Conference
International Conference on Engineering Design : 15/08/2011 - 19/08/2011
Note
Validerad; 2012; 20120411 (ysko)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-05-29Bibliographically approved
Sandberg, M., Kokkolaras, M., Tyapin, I., Isaksson, O., Aidanpää, J.-O. & Larsson, T. (2011). A knowledge-based master-model approach with application to rotating machinery design (ed.). Paper presented at . Concurrent Engineering - Research and Applications, 19(4), 295-305
Open this publication in new window or tab >>A knowledge-based master-model approach with application to rotating machinery design
Show others...
2011 (English)In: Concurrent Engineering - Research and Applications, ISSN 1063-293X, E-ISSN 1531-2003, Vol. 19, no 4, p. 295-305Article in journal (Refereed) Published
Abstract [en]

Novel rotating machinery design concepts and architectures are being explored to reduce mass, energy consumption, manufacturing costs, and environmental impact while increasing performance. As component manufacturers supply parts to original equipment manufacturers, it is desirable to design the components using a systems approach so that they are optimized for system-level performance. To accomplish that, suppliers must be able to model and predict the behavior of the whole machinery. Traditional computer-aided design/computer-aided engineering master-modeling approaches enable manual changes to be propagated to linked models. Novel knowledge-based master-modeling approaches enable automated coordination of multidisciplinary analyses. In this article, we present a specific implementation of such a knowledge-based master-modeling approach that facilitates multidisciplinary design optimization of rotating machinery. The master-model (MM) approach promotes the existence of a single governing version of the product definition as well as operating scenarios. Rules, scripts, and macros link the MM to domain-specific models. A simple yet illustrative industry application is presented, where rotor-dynamics and displacement analyses are performed to evaluate relocation alternatives for the rear bearing position of a rotating machinery under a ‘fan-blade-off’ load case.

National Category
Other Engineering and Technologies not elsewhere specified Applied Mechanics
Research subject
Functional Product Development; Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-10909 (URN)10.1177/1063293X11424511 (DOI)000297701300003 ()2-s2.0-83455201770 (Scopus ID)9cce8e00-f3ef-11df-8b36-000ea68e967b (Local ID)9cce8e00-f3ef-11df-8b36-000ea68e967b (Archive number)9cce8e00-f3ef-11df-8b36-000ea68e967b (OAI)
Note
Validerad; 2011; 20101119 (marsan)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Drignei, D., Mourelatos, Z., Kokkolaras, M., Li, J. & Koscik, G. (2011). A Variable-Size Local Domain Approach to Computer Model Validation in Design Optimization (ed.). Paper presented at SAE World Congress : 12/04/2011 - 14/04/2011. SAE International Journal of Materials & Manufacturing, 4(1), 421-429
Open this publication in new window or tab >>A Variable-Size Local Domain Approach to Computer Model Validation in Design Optimization
Show others...
2011 (English)In: SAE International Journal of Materials & Manufacturing, ISSN 1946-3979, E-ISSN 1946-3987, Vol. 4, no 1, p. 421-429Article in journal (Refereed) Published
Abstract [en]

A common approach to the validation of simulation models focuses on validation throughout the entire design space. A more recent methodology validates designs as they are generated during a simulation-based optimization process. The latter method relies on validating the simulation model in a sequence of local domains. To improve its computational efficiency, this paper proposes an iterative process, where the size and shape of local domains at the current step are determined from a parametric bootstrap methodology involving maximum likelihood estimators of unknown model parameters from the previous step. Validation is carried out in the local domain at each step. The iterative process continues until the local domain does not change from iteration to iteration during the optimization process ensuring that a converged design optimum has been obtained. The proposed methodology is illustrated using a thermal, one-dimensional, linear heat conduction problem in a solid slab with heat flux boundary conditions

Identifiers
urn:nbn:se:ltu:diva-35748 (URN)10.4271/2011-01-0243 (DOI)a6702d89-1594-4e3e-aa79-441c8826913f (Local ID)a6702d89-1594-4e3e-aa79-441c8826913f (Archive number)a6702d89-1594-4e3e-aa79-441c8826913f (OAI)
Conference
SAE World Congress : 12/04/2011 - 14/04/2011
Note

Upprättat;2011;20110822 (andbra); Konferensartikel i tidskrift;Bibliografisk uppgift: Paper Presented At: SAE 2011 World Congress & Exhibition ,2011-04-12 ,Detroit, Michigan, United States.

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-04-20Bibliographically approved
Hoffenson, S., Arepally, S., Kokkolaras, M. & Papalambros, P. Y. (2011). Ground Vehicle Safety Optimization Considering Blastworthiness and the Risks of High Weight and Fuel Consumption (ed.). Paper presented at Ground Vehicle Systems Engineering and Technology Symposium : 09/08/2011 - 11/08/2011. Paper presented at Ground Vehicle Systems Engineering and Technology Symposium : 09/08/2011 - 11/08/2011.
Open this publication in new window or tab >>Ground Vehicle Safety Optimization Considering Blastworthiness and the Risks of High Weight and Fuel Consumption
2011 (English)Conference paper, Oral presentation only (Refereed)
Identifiers
urn:nbn:se:ltu:diva-26857 (URN)01d5edf6-685a-4d02-adf2-5938eb97ca6a (Local ID)01d5edf6-685a-4d02-adf2-5938eb97ca6a (Archive number)01d5edf6-685a-4d02-adf2-5938eb97ca6a (OAI)
Conference
Ground Vehicle Systems Engineering and Technology Symposium : 09/08/2011 - 11/08/2011
Note
Upprättat; 2011; 20110905 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Organisations

Search in DiVA

Show all publications