• Strain rate in a concrete target due to high velocity projectile impact numerically simulated using LS-DYNA

      Advanced Protective Materials

      The Centre features state-of-art technological advances in the development of novel high performance protective materials to address the challenges involved in protecting both defence and civil structures against threats such as blast, fragments, and fire, etc.

    • Static lateral load tests on prototype masonry walls

      Protective Structures:

      The Centre is well known for its capabilities and innovation in research on protective structures. This includes the studies on design of structures against blast and impact loadings, retrofitting of existing structures, rapid structural repair methodologies, etc, to enhance resilience and recovery of critical infrastructures.


    • Computed Stress Contours in the Pore Water at 2.4ms after the Trigger

      Soil-Structure Interaction:

      Singapore’s geology is highly variable and heterogeneous. The Centre has undertaken a key role in the study of interaction between soil and infrastructure in challenging geological profiles during both construction and in operation. The Centre also form the basis of research synergy between investigators across several disciplines to ensure reliable and long term operation of critical buildings and lifelines in times of peace and emergency.


    • Complex P, S and R wavefields due to point source excitation

      Soil Dynamics:

      The Centre is actively involved in a variety of soil dynamics in geotechnical engineering and geophysics, such as wave propagation, ground vibration, shock and impact. Research applications include detection of cavities in soils, non-invasive assessment of strength of soils and rocks, soil liquefaction vulnerability, shear modulus degradation, etc, using the Centre’s state-of-art experimental facilities and in-house numerical simulation capabilities.


    • Analysis of buried pipes subjected to shock and impact loads


      The project investigates the structural response of buried pipes due to external loads, in particular due to sub-surface bomb blasts. Finite element analysis is employed to provide computational analysis due to the high complexity of the problem, which include solid-solid interaction, soil-structure interaction, progressive damage modelling and blast loads.

      Extensive material characterization tests, such as uniaxial mechanical tests of pipe coupons at high and low strain rates, multiaxial loading mechanical tests of pipe sections and geotechnical centrifuge blast tests are carried out to determine suitable material models and parameters used in the simulations.
      Towards the end of the project, a full scale blast test will be carried out to verify simulation results.


      Contact: A/Prof Vincent Tan Beng Chye


      Read More

    • Effect of High Strain Rate on Compressive Behavior of High Performance Fiber-Reinforced Cement Composites


      The main objective of this project is to have a better understanding on the behavior of fiber reinforced cement composites when subjected to high strain rate compressive loading. Behavior of two strain-hardening cement composites (SHCCs) and two fiber-reinforced high-strength concretes (FRHSCs) of similar compressive strengths is investigated with static, intermediate, and high strain rate compressive loadings. One of the SHCCs was reinforced with 2% of polyvinyl alcohol fibers by volume and had a compressive strength of 64 MPa. The other was reinforced with 0.5% of steel plus 1.5% of polyethylene fibers by volume and had a compressive strength of 83 MPa. Both FRHSCs were reinforced with 0.5% of steel fibers. The strain rates from 10-5 to about 300 s-1 are generated by a hydraulic testing machine and a split Hopkinson pressure bar system.

      The Dynamic Increase Factor (DIFfc), the ratio of the compressive strength under dynamic loading to that under static loading, is determined. Experimental results indicate that the fiber content has a significant effect on the DIFfc value. At a similar strain rate level, the damage of the SHCC specimens is less severe than that of the FRHSC specimens, and the DIFfc of the former is lower than that of the latter.


      Contact: Prof Zhang Min-Hong


      Read More

    • Resistance of High Performance Fiber-Reinforced Cement Composites against High-Velocity Projectile Impact


      Resistance of fiber-reinforced cement composites with compressive strengths from 60 to 140 MPa against high-velocity projectile impact is investigated to provide guidance on the selection of materials for protective structures. Seven composites including two strain-hardening cement composites (SHCCs), four fiber-reinforced high-strength concretes (FRHSCs), and one fiber-reinforced high strength mortar (FRHSM) are evaluated. Ogive-nose shaped projectiles, with a diameter of 28 mm and weight of about 250 g, are used for tests with impact velocities of about 400 and 600 m/s. Numerical study is also conducted to simulate the localized damage of the SHCC and FRHSC specimens using a finite element software LS-DYNA.

      Experimental results indicate that higher compressive strength and greater toughness of cement-based composites, as well as the presence of strong coarse aggregate and fibers, contribute positively to the impact resistance of composites. In addition, it was found that the penetration depth of the composites subjected to high-velocity projectile impact is reduced with an increase in the “effective hardness index” calculated based on the hardness and proportion of the coarse aggregate and mortar matrix. Numerical simulation results indicate that it takes a longer time to stop the projectile traveling at the same initial velocity in the SHCC specimen than in the FRHSC specimen due to the absence of hard and strong coarse aggregate in the former.


      Contact: Prof Zhang Min-Hong


      Read More

    • High Performance Concrete for Protective Structures – Part B: Characterisation and Constitutive Modelling of Dynamic Response of HSC and Establishment of a High-Capacity Ballistic Testing Facility


      This project focuses on the dynamic properties of high-strength concretes (HSCs) and their performance in protection against projectile impact. It encompasses experimental characterisation and constitutive modelling of the dynamic material response of HSC, and ballistic tests on HSC targets. Tensile and compressive static and dynamic tests were performed on three HSCs with different strengths, to examine the effects of strain rate on their mechanical properties – i.e. stress-strain relationship, compressive/tensile strength – and how these vary with concrete strength.

      A 3D finite element (FE) model for HSC was also developed; the model incorporates details of the HSC meso-structure – i.e. random distribution of coarse aggregate particles within the mortar matrix, and a cohesive surface between the aggregate particles and the mortar matrix via an interfacial transition zone. This meso-scale FE model yields reasonable estimates of the HSC response, based on the properties of the constituent mortar and coarse aggregate prescribed to it.


      Contact: Prof Victor Shim


      Read More

    • In-structure shock analysis and validation


      Analytical method usually involves the usage of single-degree-of-freedom (SDOF) or multi-degree-of-freedom (MDOF) models to idealize the structural element under consideration and these models utilize the first few modes to predict the structure’s response to blast loading. The aim of the study is to develop numerical finite element models to predict the structural response and subsequent in-structure shock loading within surface and subsurface structures for various blast scenarios. The results obtained will be compared with Single-Degree-of-Freedom (SDOF) models used for the predictions of in-structure shock loads to provide guidance in the appropriate usage of the SDOF models.


      Contact: A/Prof Vincent Tan Beng Chye


      Read More

    1. Journal Paper

      Chian SC, Tan VBC and Sarma A, Projectile Penetration into Sand: Relative Density of Sand and Projectile Nose Shape and Mass, Int Journal of Impact Engineering, 103, 29-37. DOI.10.1016/j.ijimpeng.2017.01.002.

      WANG, S, H T N LE, L H POH, S T Quek and M H Zhang, Effect of High Strain Rate on Compressive Behavior of Strain-Hardening Cement Composite in Comparison to that of Ordinary Fiber-Reinforced Concrete, Construction and Building Materials, 136 (2017): 31-43.

    2. Journal Paper

      WANG, S, H T N LE, L H POH, H FENG and M H Zhang, Resistance of High-Performance Fiber-Reinforced Cement Composites against High-Velocity Projectile Impact, International Journal of Impact Engineering, 95 (2016): 89-104.

      FENG, H, H T N LE, S WANG and M H Zhang, Effects of Silanes and Nano-Sized Silane Derivatives on Cement Hydration and Mechanical Properties of Mortars, Construction and Building Materials, 129 (2016): 48-60.

      Conference Paper

      Zhang, M H, H T N LE, S WANG, L H POH and H FENG, Resistance of Fiber-Reinforced High-Strength Concretes and Strain Hardening Cement Composites to High Velocity Projectile Impact, 8th International Conference on Concrete Under Severe Conditions-Environment & Loading, 12 - 14 Sep 2016, Polytech Milano, Lecco, Italy.

      V.P.W. Shim, Y.B. Guo, G.F. Gao, Projectile Penetration of High-Strength Concrete – Experiments and Numerical Simulation, 2nd International Forum on Specialized Equipment and Engineering Mechanics, July 27-28, 2016, Nanjing, China.

      Y.B. Guo, G.F. Gao, V.P.W. Shim, Dynamic compressive properties of granite rock, Oral presentation, IFSEEM 2016 – 2nd International Forum on Specialized Equipment and Engineering Mechanics, July 27-28, 2016, Nanjing, China.

    3. Journal Paper

      Ong C W R, Zhang M H, Du H, and Pang S D, Cellular Cement Composites Against Projectile Impact, Int Journal of Impact Engineering, 86, P13-26.

      Conference Paper

      Abraham C and Ong K.C.G, Performance Of Fibre Reinforced Concrete With Steel Sandwich Composite Panel Under Close-In Blast Loading, Proceedings Of International Conference On Concrete And Infrastructure 2015 (ICCI 2015) Semarang, Indonesia, October 28th - 30th, 2015 (Will Be Listed In International Journal Of Science And Engineering).

      N.T. Cao, Y.B. Guo, G.F. Gao, V.P.W. Shim, Meso-scale Computational Modeling of High-Strength Concrete, Oral presentation, ICMM4 – 4th International Conference on Material Modeling, May 27-29, 2015, Berkeley, California.

      WANG, S, H T N LE, L H POH and M H Zhang, Effect Of High Strain Rate Loading On Compressive Behavior Of Strain-Hardening Cementitious Composite, Design and Analysis of Protective Structrues, ed. Mark Stewart, Michael Netherton (2015): 671-678. 3rd International Conference on Protective Structures, 3 - 6 Feb 2015, Crowne Plaza Newcastle, Newcastle, Australia.

      Chian SC, Tan VBC & Sarma A, Impact Resistance of Sand against Projectile Penetration, 5th International Conference on Design and Analysis of Protective Structures, Singapore, pp. 312-317.

    4. Journal Paper

      Chai H Y, Goh SH, Phoon KK and C F Wei, Effects Of Source And Cavity Depths On Wave Fields In Layered Media, Journal of Applied Geophysics, Vol 107, Pp 163-170

      Ye F., Goh S.H. and Lee F.H., Dual-Phase Coupled U-U Analysis Of Wave Propagation In Saturated Porous Media Using A Commercial Code, Computers And Geotechnics; 55,316-329.

      Conference Paper

      Shim V P W, Y B Guo and L Jing, Response of High Strength Concrete to Dynamic Loading, 16th International Conference on Experimental Mechanics (7 – 11 July 2014), University Of Cambridge, UK.

      Ye F, C H Yeo, S H Goh, S Anand and T B Soh, 3d Numerical Modeling of Underground Explosion in Saturated Sand, Proceeding of 8th European Conference on Numerical Methods in Geotechnical Engineering, Delft, The Netherlands.

      Yeo C H, Goh S H, Anand S and Soh T B, Pore Pressure Responses Of A Buried Blast In Saturated Sand, 8th International Conference On Physical Modelling In Geotechnics 2014, Perth, Australia, 14-17 January 2014.

    5. Journal Paper

      Chai, H Y, S H GOH, K K Phoon and C F Wei, "Effects of source and cavity depths on wave fields in homogeneous half spaces", Journal of Applied Geophysics (In Press).

      Conference Paper

      Ye F., Goh S.H. and Lee F.H., Solving The Wave Propagation In Fully Saturated Porous Media Using Dual Mesh Method, International Conference Of Numerical Analysis And Applied Mathematics. AIP Conf. Proc. 1558, 2448. Rhodes, Greece.

      Xiao H, Goh S.H., Lee F.H., Lee C.H. and Sarma A, Numerical Study On Blast Induced Wave Propagation In Saturated Sands, Proceedings Of The 18th South East Asian Geotechnical Conference, Ed. Leung, Goh & Shen., South East Asian Geotechnical Conference, Vol. 18 (2013): 1087 1093.

      Xiao H, Goh S.H., Lee F.H., Sarma A. and Lee C.H., Undrained Pore Pressure Response Of Sand Under Different Modes Of Cyclic Loading, Proceedings Of The 18th South East Asian Geotechnical Conference, Ed. Leung, Goh & Shen., South East Asian Geotechnical Conference, Vol. 18 (2013): 479 484.

      Y Wang, J Y R Liew and S C Lee, Theoretical Models for Axially-Restrained Steel-Concrete-Steel Sandwich Panels under Blast Loads, Shock & Impact Loads on Structures (25 - 26 Nov 2013), Singapore

      Y Wang, J Y R Liew and S C Lee, High Velocity Airbag Impact Test on Water Tank, 26th KKHTCNN Symposium on Civil Engineering (18 - 20 Nov 2013)

      WANG, S and M H Zhang, Determination of Specimen Sizes of Concrete subjected to Static Loading in Comparison to Those from Split Hopkinson Bar Test for Computation of Dynamic Increasing Factor, High speed imaging for dynamic testing of materials and structures, 21st DYMAT Technical Meeting, 18 - 20 Nov 2013, Institute of Physics, London, United Kingdom.

      Zheng M, S C Lee, J Y R Liew and Y Wang, Heat Transfer Analysis of Building Wall System with Water Tank Attached, 10th Pacific Structural Steel Conference: Advancements and Achievements in Structural Steel (8 - 11 Oct 2013). Singapore.

      Y Wang, J Y R Liew and S C Lee, Development of P-I Diagram for One-Way Supported Structure Considering Tensile Membrane Effect, 25th KKCNN Symposium on Civil Engineering (22 - 24 Oct 2013). Busan, South Korea.

      J Y R Liew, Zheng M, S C Lee and WB Ho, Energy Collecting Performance of Building Integrated Water Storage Facade System for Hot Climate Application, Sustainable Building Conference (Sb 13): Realising Sustainability in the Tropics (9 - 10 Sep 2013). Singapore.

    6. Journal Paper

      Chai, H Y, K K Phoon, S H GOH and C F Wei, "Some theoretical and numerical observations on scattering of Rayleigh waves in media containing shallow rectangular cavities", Journal of Applied Geophysics, 83 (2012): 107-119.

      WANG, S, M H Zhang and S T Quek, "Mechanical Behavior of Fiber-Reinforced High-Strength Concrete Subjected to High Strain-Rate Compressive Loading", Construction and Building Materials, 31 (2012): 1-11.

      Conference Paper

      Soon Hoe CHEW, Andy Hong Wei TAN, Heng Kek CHOO, Karen CHONG, Joel ONG, Chor Boon NG, "Fast Running Prediction Framework for Indoor Blast: Blast Prediction", DAPS 2012: 4th International Conference on Design & Analysis of Protective Structures, 19 -22 Jun 2012, Hyatt Regency, Jeju,Jeju South Korea.

      WANG, S. M H Zhang and S T Quek, "Static and Dynamic Compressive Behavior of Fiber-Reinforced High-Strength Concrete", DAPS 2012: The 4th International Conference on Design and Analysis of Protective Structures, 19 - 22 Jun 2012, Hyatt Regency Jeju, Jeju, South Korea.

    7. Journal Paper

      Wang, S, M H Zhang and S T Quek, "Effect of Specimen Size on Static Strength and Dynamic Increase Factor of High-Strength Concrete from SHPB Test", Journal of Testing and Evaluation, 39(5) (2011) p.898-907.

      Wang, S, M H Zhang and S T Quek, "Tensile Strength versus Toughness of Cement-Based Materials against High-Velocity Projectile Impact", International Journal of Protective Structures, 2, no. 2 (2011): 207- 219.

      Wang, S, M H Zhang and S T Quek, "Effect of High Strain Rate Loading on Compressive Behavior of Fiber-Reinforced High-Strength Concrete", Magazine of Concrete Research, 63(11) (2011) p. 813-827.

      Sohel KMA, Liew JYR, Zhang MH, "Design of Steel-Concrete Composite Sandwich Systems against Extreme Loads", Frontiers of Architecture and Civil Engineering in China 2011 (published by Springer). Vol 5, No.3, pp. 278–293.

      Conference Paper

      Koh, CG, S. Swaddiwudhipong, Z S Liu and M Gao, "Particle Methods for Modelling Impact Load on Structures" (keynote), Proceedings of the 9th International Conference on Shock & Impact Loads on Structures, 16-18 November 2011, Fukuoka, Japan, pp. 41-56

      Wang, S, M H Zhang and S T Quek, "Effect of High Strain Rate Loading on Compressive Behavior of Fiber-Reinforced High-Strength Concrete", Magazine of Concrete Research, 63(11) (2011) p. 813-827.

      Tan, H W A, S H Chew, Z.W. HE and S Anand, "Numerical Simulation of Non-Concrete Earth Walls", Proceedings of 10TH Australian Explosive Ordnance Symposium (2011). Brisbane, Queensland: THALES Australia. (Invited paper) (10TH Australian Explosive Ordnance Symposium (PARARI 2011), 8 - 10 Nov 2011, Sofitel Hotel, Brisbane, Australia)

      Ye F.J., Goh S. H. and Lee F. H., "Two/Three dimensional finite element analysis of fluid solid interaction using the ADPC method", Proceeding of International Symposium on Advances in Ground Technology and Geo-Information, Singapore, 2011.

      Ye F.J., Goh S. H. and Lee F. H., "Numerical study on wave propagation from dry to saturated sand", The twenty-fourth KKCNN symposium on civil Engineering, Hyogo, Japan, 2011.

    8. Journal Paper

      Liew JYR, Sohel KMA, " Structural Performance of Steel-Concrete-Steel Sandwich Composite Structures", Advances in Structural Engineering, 2010, Vol. 13(3) (2010) 453-470.

      Conference Paper

      Ye, F, Goh, S. H. & Lee, F. H. (2010), "A Method to Solve Biot's u-U Formulations for Soil Dynamics Applications using the ABAQUS/Explicit Platform", Proceedings of the 7th European Conference on Numerical Methods in Geotechnical Engineering, eds. Benz and Nordal, 1 - 4 Jun 2010, Norwegian University of Science and Technology, Trondheim, Norway.

      Chew, S. H., Tan, H. W. Andy, He, Z.W. & Anand, S. (2010), "Use of Geosynthetics Reinforced Soil for Blast Protection & Ground Shock Mitigation", MABS 21 Symposium (Military Aspects of Blast & Shock), October 2010, Jerusalem, Israel.

      Chew, S. H., Tan, H. W. Andy & He, Z.W. (2010), "Military Applications of Rapidly Constructed Non-Concrete Earth Walls – Design & Construction", MABS 21 Symposium (Military Aspects of Blast & Shock), October 2010, Jerusalem, Israel.

      Wu, J. & Chew, S. H. (2010), "Evaluation of RHT Model in AUTODYN Modelling of Blast Loading on Slab", The 23rd KKCNN Symposium on Civil Engineering, Nov 2010, Taiwan.

      Chew, S. H., Tan, H. W. Andy & He, Z.W. (2010), "Blast Protection and Ground Shock Mitigation using Geosynthetics", Proceedings of Design and Analysis of Protective Structures Conference (DAPS2010), May 2010, Singapore.

      Tan, H. W. Andy, Chew, S. H., & He, Z.W. (2010), "Laboratory Drop Weight Impact Tests on Geogrid Reinforced Pavements", Proceedings of 9th International Conference on Geosynthetics (9th ICG), May 2010, Brazil.

      Wang, S, M H Zhang and S T Quek, "Tensile Strength versus Toughness of Cement-Based Materials against High-Velocity Projectile Impact", The First International Conference of Protective Structures, ed. Q.M.Li, H.Hao, Z.X.Li and D.Yankelevsky (2010), 30 Sep - 1 Oct 2010, Manchester Conference Centre, Manchester, United Kingdom.

      Wu, J and S H Chew, "Evaluation Of RHT Concrete Model In Autodyn For Simulation Of Concrete Material Subjected To Blast Loading", The 23rd KKCNN Symposium on Civil Engineering, 13-15 Nov, 2010, Taipei, Taiwan

      Chew, S H, H W A Tan, Z W HE and S ANAND, "Military Applications Of Rapidly Constructed Non-Concrete Earth Walls – Design & Construction", MABs 21 Symposium – Military Aspects Of Blast And Shock (2010). Jerusalem: Ben-Gurion University. (Invited Paper) (MABs 21 Symposium – Military Aspects Of Blast And Shock, 3 - 8 Oct 2010, Inbal Jerusalem Hotel, Jerusalem, Israel)

      Tan, H W A, S H Chew, Z W HE and S Anand, "Use Of Geosynthetics Reinforced Soil For Blast Protection & Ground Shock Mitigation", MABs 21 Symposium – Military Aspects Of Blast And Shock (2010). Jerusalem: Ben-Gurion University. (Invited Paper) (MABs 21 Symposium – Military Aspects Of Blast And Shock, 3 - 8 Oct 2010, Inbal Jerusalem Hotel, Jerusalem, Israel)

      Tan, H W A, S H Chew and Z.W. HE, "Laboratory Drop Weight Impact Tests on Geogrid Reinforced Pavements", 9th International Conference on Geosynthetics – 9ICG (2010). SAO PAOLO. (9th International Conference on Geosynthetics – 9ICG, 24 - 27 May 2010, Sofitel Jequitimar Convention Center, SAO PAOLO, Brazil)

      Ye F. J., Goh S. H. and Lee F. H., "A method to solve Biot's u-U formulations for soil dynamics applications using the ABAQUS/Explicit platform", Proceeding of 7th European Conference on Numerical Methods in Geotechnical Engineering, Trondheim, Norway, 2010, pp 417-422.

      Jia-baoYan, Sohel KMA, Liew JYR, Choo YS, "Novel shear connectors for composite sandwich structures", Proceedings of the Twenty-third KKCNN Symposium on Civil Engineering, November 13–15, 2010, Taipei, Taiwan, pp 77-80.

    9. Journal Paper

      Liew JYR, Sohel KMA, Koh CG, "Impact Tests on Steel-Concrete-Steel Sandwich Beams with Lightweight Concrete Core", Engineering Structures, 31 (9) (2009), 2045-2059.

      Liew JYR, Sohel KMA., "Lightweight Steel-Concrete-Steel Sandwich System with J-hook Connectors", Engineering Structures, 2009, Vol. 31(5), pp. 1166-1178.

      Conference Paper

      Chew, S. H., Tan, H. W. Andy, He, Z.W. & Anand, S. (2009), "Application of Rapidly Constructed Non-concrete Earth Walls for Munitions Storage", Proceedings of 9th Australian Explosive Ordnance Symposium (PARARI2009), November 2009, Adelaide, Australia.

      Wu, J and S H Chew, "Numerical Simulation Of Concrete Slab Subject To Blast Loading", The 22th KKCNN Symposium on Civil Engineering, 31 Oct - 2 Nov, 2009, Thailand.

      Tan, H W A and S H Chew, "Behavior Of Geosynthetics Reinforced Walls & Trenches For Blast Protection", ISGI09 (International Symposium on Ground Improvement Technologies and Case Histories), 9 - 11 Dec 2009, Furama Riverfront Hotel, Singapore.

      Tan, H W A and S H Chew, "Behavior Of Geosynthetics Reinforced Walls & Trenches For Blast Protection", ISGI09 (International Symposium on Ground Improvement Technologies and Case Histories), ed. NUS, comp. NUS (2009). Singapore: NUS. (Invited paper) ( ISGI09 (International Symposium on Ground Improvement Technologies and Case Histories), 9 - 11 Dec 2009, Furama Riverfront Hotel, Singapore)

      Chew, S H, H W A Tan, Z.W. HE and S Anand, "Application of Rapidly Constructed Non-concrete Earth Walls", 9th Australian Explosive Ordnance Symposium (PARARI 2009) (2009). Glenelg, Adelaide: THALES. (9th Australian Explosive Ordnance Symposium (PARARI 2009), 10 - 12 Nov 2009, Stamford Grand, Glenelg, Adelaide, Australia).

      Patria, K and K C G Ong, "Performance of Hybrid fiber ECC on RC Column's Retrofitting Subjected to Blast Loading", International Conference on Computational Design in Engineering, CODE 2009 (2009). Seoul: Computational Structural Engineering Institute of Korea. (Invited paper) (International Conference on Computational Design in Engineering CODE 2009, 3 6 Sep 2009, Imperial Palace Hotel, Seoul, South Korea)

      Ong, K C G, K PATRIA and Soh Tian Boon, "Finite Element Analysis and Testing of Quarter scale RC Columns with and without ECC Encasement subjected to Close in Explosion", The Second International Workshop on Performance, Protection & Strengthening of Structures under Extreme Loading (2009). Hayama: National Defense Academy Japan. (Plenary paper) (PROTECT2009, 19 21 Aug 2009, Hayama, Japan)

      Sohel KMA, Liew JYR, Wang TY and Kang KW, "Sandwich Composite Structures Subjected to Impact and Blast", Proceedings of the Twenty-second KKCNN Symposium on Civil Engineering, October 31–November 2, 2009, The Imperial Mae Ping Hotel, Chiang Mai, Thailand, pp.79-82.

      JYR Liew, SC Lee and KMA Sohel, "Ultra-Lightweight Steel-Concrete-Steel Sandwich Composite Panels Subjected to Impact", Proceedings of the 5th International Symposium on Steel Structures March 12-14, 2009, Seoul, Korea. P.586-593.