SavedAdd your journal

Journals / Erciyes Üniversitesi Fen Bilimleri Enstitüsü Fen Bilimleri Dergisi / 2026 / Cilt: 42 Sayı: 1

Investigation of the Effects of Concave and Convex Conditions of Steel Guardrails Installed Inside Curves on the Safety Parameters According to the EN 1317 Standard Using Finite Element Analysis

Dönemeç İçine İnşa Edilen Çelik Otokorkulukların Konkav ve Konveks Durumlarının En 1317 Standardındaki Güvenlik Parametrelerine Etkisinin Sonlu Elemanlar Analizi ile Araştırılması

Sedat Ozcanan(SIRNAK UNIVERSITY)0000-0002-8504-7611
Özgür Özcan(ŞIRNAK ÜNİVERSİTESİ)0000-0001-5039-2477
Zeynel Acar(ŞIRNAK ÜNİVERSİTESİ)0000-0002-6858-1521
Pages
—
Publication Date
2026-03-26
🏛️Bibliographic metadata and full text access for this article are provided via DergiPark.
DergiPark Record ↗
✨

AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

The results indicate that concave guardrails generally exhibit reduced impact severity, reflected by lower ASI and THIV values, compared to straight-road cases.

📌 3 Key Takeaways

🎯
Objective & Hypothesis:Steel guardrail systems play a critical role in reducing injury severity during run-off-road crashes, especially on horizontal curves where accident rates are high.
📊
Key Findings & Data:However, validation procedures defined in the EN 1317 standard are predominantly based on crash tests performed on straight road sections, and the influence of curved geometries is not sufficiently considered.
💡
Conclusion & Impact:The results indicate that concave guardrails generally exhibit reduced impact severity, reflected by lower ASI and THIV values, compared to straight-road cases.
🔬Design:Modeling & Simulation
📍Scope:Comprehensive Sample
⚙️Variables:Yatay Kurp · Otokorkuluk · EN1317

Abstract

Steel guardrail systems play a critical role in reducing injury severity during run-off-road crashes, especially on horizontal curves where accident rates are high. However, validation procedures defined in the EN 1317 standard are predominantly based on crash tests performed on straight road sections, and the influence of curved geometries is not sufficiently considered. This study numerically examines the effects of concave and convex horizontal curves on the safety performance of steel guardrails using finite element analysis (FEA). An EN 1317-compliant H1W4-A steel guardrail system was developed and validated under TB11 crash test conditions using LS-DYNA. The validated model was subsequently applied to concave and convex curve configurations with radii between 30 m and 210 m, resulting in a total of 14 numerical crash simulations. Key occupant safety parameters, namely the Acceleration Severity Index (ASI) and Theoretical Head Impact Velocity (THIV), together with structural performance measures such as working width (W) and exit angle (α), were systematically evaluated and compared with straight-road reference conditions. The results indicate that concave guardrails generally exhibit reduced impact severity, reflected by lower ASI and THIV values, compared to straight-road cases. In contrast, convex guardrails lead to higher and more critical safety indices, particularly at smaller radii. Although most configurations remain within EN 1317 limits, the R30 concave case exceeds allowable exit angle and working width thresholds. These findings highlight the necessity of incorporating road curvature effects into guardrail safety assessments.

Özet

Çelik otokorkuluk sistemleri, özellikle kaza oranlarının yüksek olduğu yatay kurplarda meydana gelen yoldan çıkma kazalarında yaralanma şiddetinin azaltılmasında kritik bir rol oynamaktadır. Ancak EN 1317 standardında tanımlanan doğrulama prosedürleri ağırlıklı olarak düz yol kesitlerinde gerçekleştirilen çarpışma testlerine dayanmaktadır ve eğrisel yol geometrilerinin etkisi yeterince dikkate alınmamaktadır. Bu çalışmada, konkav ve konveks yatay kurpların çelik otokorkuluk sistemlerinin güvenlik performansı üzerindeki etkileri sonlu elemanlar analizi (SEA) kullanılarak sayısal olarak incelenmiştir. EN 1317 ile uyumlu H1W4-A çelik otokorkuluk sistemi, TB11 çarpışma testi koşulları altında LS-DYNA yazılımı kullanılarak modellenmiş ve doğrulanmıştır. Doğrulanan model, 30 m ile 210 m arasında değişen yarıçaplara sahip konkav ve konveks kurp konfigürasyonlarına uyarlanmış ve toplam 14 adet sayısal çarpışma simülasyonu gerçekleştirilmiştir. Çalışmada, Hızlanma Şiddet İndeksi (ASI) ve Teorik Baş Çarpma Hızı (THIV) gibi yolcu güvenliğine ilişkin parametreler ile çalışma genişliği (W) ve çıkış açısı (α) gibi yapısal performans ölçütleri sistematik olarak değerlendirilmiş ve düz yol referans koşulları ile karşılaştırılmıştır. Elde edilen sonuçlar, konkav otokorkuluk sistemlerinin düz yol koşullarına kıyasla daha düşük ASI ve THIV değerleri sergileyerek daha az darbe şiddeti oluşturduğunu göstermektedir. Buna karşılık, konveks otokorkuluk sistemlerinin özellikle küçük yarıçaplı kurplarda daha yüksek ve kritik güvenlik seviyelerine yol açtığı belirlenmiştir. Çoğu konfigürasyon EN 1317 sınır değerleri içinde kalmasına rağmen, R30 konkav durumunda izin verilen çıkış açısı ve çalışma genişliği limitlerinin aşıldığı tespit edilmiştir. Bu bulgular, otokorkuluk güvenlik değerlendirmelerinde yol geometrisinin etkisinin mutlaka dikkate alınması gerektiğini ortaya koymaktadır.

🔖

Cite This Article

Ozcanan, S., Özcan, Ö., Acar, Z. (2026). Investigation of the Effects of Concave and Convex Conditions of Steel Guardrails Installed Inside Curves on the Safety Parameters According to the EN 1317 Standard Using Finite Element Analysis. Erciyes Üniversitesi Fen Bilimleri Enstitüsü Fen Bilimleri Dergisi, Cilt: 42 Sayı: 1. https://doi.org/10.65520/erciyesfen.1791972

📄 Full Text PDF Viewer

📄

PDF görüntüleyici hazırlanıyor...

References (41)

  1. Ma, Q., Yang, H., Wang, Z., Xie, K., Yang, D. 2020. Modeling crash risk of horizontal curves using large-scale auto-extracted roadway geometry data. Accident Analysis and Prevention, 144(2020), 105669. https://doi.org/10.1016/j.aap.2020.105669
  2. NHTSA. 2020. Fatality Analysis Reporting System. http://www-fars.nhtsa.dot.gov/Main/index.aspx (Access date: 09.04.2023).
  3. FHWA. 2019. Horizontal Curve Safety. https://safety.fhwa.dot.gov/roadway_dept/countermeasures/horicurves/ (Access date: 14.03.2022).
  4. European Transport Safety Council (ETSC). 2017. Reducing Deaths in Single Vehicle Collisions. PIN Flash Report No. 32. https://etsc.eu/wp-content/uploads/PIN_FLASH32-FINAL.pdf (Access date: 17.07.2024).
  5. Peng, J., Chu, L., Wang, T., Fwa, T. F. 2021. Analysis of vehicle skidding potential on horizontal curves. Accident Analysis and Prevention, 152(2021), 105960. https://doi.org/10.1016/j.aap.2020.105960
  6. Wood, J., Donnell, E. T. 2020. Empirical Bayes before-after evaluation of horizontal curve warning pavement markings on two-lane rural highways in Pennsylvania. Accident Analysis and Prevention, 146(2020), 105734. https://doi.org/10.1016/j.aap.2020.105734
  7. Atahan, A. O., Bonin, G., Karacasu, M. 2007. Development of a 30,000 kg heavy goods vehicle for LS-DYNA applications. International Journal of Heavy Vehicle Systems, 14(1)(2007), 1–19. https://doi.org/10.1504/IJHVS.2007.011929
  8. EN 1317-1:2010, Road restraint systems - Part 1: Terminology and general criteria for test methods. 2010.
  9. EN1317-2:2010, Road restraint systems - Part 2: Performance classes, impact test acceptance criteria and test methods for safety barriers including vehicle parapets Dispositifs. 2010.
  10. Sicking, D. L. 1995. Applications of simulation in design and analysis of roadside safety features. Transportation Research Circular, 435(1995).
  11. Ray, M. H. 1996. Repeatability of full-scale crash tests and criteria for validating simulation results. Transportation Research Record, 1528(1996), 155–160. https://doi.org/10.1177/0361198196152800117
  12. Atahan, A. O. 2002. Finite element simulation of a strong-post W-beam guardrail system. Simulation, 78(10)(2002), 587–599. https://doi.org/10.1177/0037549702078010001
  13. Ren, Z., Vesenjak, M. 2005. Computational and experimental crash analysis of the road safety barrier. Engineering Failure Analysis, 12(6)(2005), 963–973. https://doi.org/10.1016/j.engfailanal.2004.12.033
  14. Pawlak, M. 2016. The acceleration severity index in the impact of a vehicle against permanent road equipment support structures. Mechanics Research Communications, 77(2016), 21–28. https://doi.org/10.1016/j.mechrescom.2016.08.005
  15. Long, K., Gao, Z., Yuan, Q., Xiang, W., Hao, W. 2018. Safety evaluation for roadside crashes by vehicle–object collision simulation. Advances in Mechanical Engineering, 10(10)(2018), 1–12. https://doi.org/10.1177/1687814018805581
  16. Yılmaz, İ., Yelek, İ., Özcanan, S., Atahan, A. O., Hiekmann, J. M. 2021. Artificial neural network metamodeling-based design optimization of a continuous motorcyclists protection barrier system. Structural and Multidisciplinary Optimization, (2021). https://doi.org/10.1007/s00158-021-03080-1
  17. Ozcanan, S., Atahan, A. O. 2020. Radial basis function surrogate model-based optimization of guardrail post embedment depth in different soil conditions. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 234(2–3)(2020), 739–761. https://doi.org/10.1177/0954407019848548
  18. Yumrutas, H. I., Ozcanan, S., Apak, M. Y. 2022. Experimental and numerical comparative crashworthiness analysis of innovative renewable hybrid barrier with conventional roadside barriers. International Journal of Crashworthiness, (2022), 1–17. https://doi.org/10.1080/13588265.2022.2075124
  19. Klasztorny, M. 2015. Rubber/foam/composite overlay onto guide B of barrier located on road bend. Archiwum Motoryzacji, 69(2015), 65–86.
  20. Apak, M. Y., et al. 2022. Finite element simulation and failure analysis of fixed bollard system according to the PAS 68:2013 standard. Engineering Failure Analysis, 135(2022), 106151. https://doi.org/10.1016/j.engfailanal.2022.106151
  21. Chell, J., Brandani, C. E., Frascetti, S., Chakraverty, J., Camomilla, V. 2019. Limitations of the European barrier crash testing regulation relating to occupant safety. Accident Analysis and Prevention, 133(2019), 105239. https://doi.org/10.1016/j.aap.2019.07.015
  22. Li, N., Fang, H., Zhang, C., Gutowski, M., Palta, E., Wang, Q. 2015. A numerical study of occupant responses and injuries in vehicular crashes into roadside barriers based on finite element simulations. Advances in Engineering Software, 90(2015), 22–40. https://doi.org/10.1016/j.advengsoft.2015.06.004
  23. D. Naish, D. A., Burbridge, A. 2015. Occupant severity prediction from simulation of small car impact with various concrete barrier profiles. International Journal of Crashworthiness, 20(5)(2015), 510–523. https://doi.org/10.1080/13588265.2015.1048177
  24. Ozcanan, S., Ozcan, O. 2022. Criteria inadequacy of the vehicles used for the calculation of safety parameters in the EN1317-TB11 test. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, (2022). https://doi.org/10.1177/09544070221115010
  25. Pachocki, L., Bruski, D., Burzyński, S., Chróścielewski, J., Wilde, K., Witkowski, W. 2018. On the influence of the acceleration recording time on the calculation of impact severity indexes. MATEC Web of Conferences, 219(2018), 03010. https://doi.org/10.1051/matecconf/201821903010
  26. Wilde, K., Burzyński, S., Bruski, D., Chróścielewski, J., Witkowski, W. 2017. TB11 test for short W-beam road barrier. 11th European LS-DYNA Conference, 2017, Salzburg.
  27. FHWA. 2016. Low-Cost Treatments for Horizontal Curve Safety. https://rosap.ntl.bts.gov/view/dot/50421 (Access date: 01.01.2018).
  28. Wilde, K., Bruski, D., Budzyński, M., Burzyński, S., Chróścielewski, J., Jamroz, K., Pachocki, Ł., Witkowski, W. 2020. Numerical analysis of TB32 crash tests for 4-cable guardrail barrier system installed on horizontal convex curves of road. International Journal of Nonlinear Sciences and Numerical Simulation, 21(1)(2020), 65–81. https://doi.org/10.1515/ijnsns-2018-0169
  29. Budzyński, M., Bruski, D. 2018. Assessing vehicle restraint systems on horizontal curves. MATEC Web of Conferences, 231(2018), 01004. https://doi.org/10.1051/matecconf/201823101004
  30. Klasztorny, M., Zielonka, K., Nycz, D. B., Posuniak, P., Romanowski, R. K. 2018. Experimental validation of simulated TB32 crash tests for SP-05/2 barrier on horizontal concave arc without and with composite overlay. Archives of Civil and Mechanical Engineering, 18(2)(2018), 339–355. https://doi.org/10.1016/j.acme.2017.07.007
  31. Klasztorny, M., Nycz, D. B., Zajac, K. P. 2019. Modelling and simulation of crash tests on curved barriers taking into account vehicle speed limits. Baltic Journal of Road and Bridge Engineering, 14(3)(2019), 304–325. https://doi.org/10.7250/bjrbe.2019-14.445
  32. Nycz, D. B. 2017. Influence of selected design parameters of the composite-foam cover rail on the course of the TB11 crash test of a road safety barrier forming a horizontal concave arc. Archiwum Motoryzacji, 76(2)(2017), 107–122. https://doi.org/10.14669/am.vol76.art5
  33. Nasution, R. P., Siregar, R. A., Fuad, K., Adom, A. H. 2009. The effect of ASI (Acceleration Severity Index) to different crash velocities. Proceedings of the International Conference on Applications and Design in Mechanical Engineering, (2009), 11–13.
  34. Shojaati, M. 2003. Correlation between injury risk and impact severity index ASI. 3rd Swiss Transport Research Conference, 2003, Switzerland, 19–21.
  35. Ozcanan, S., Özcan, Ö. 2025. Impact angle-based section design and optimization of the C post in order to improve the safety and structural performance of guardrails. Turkish Journal of Civil Engineering, 36(3)(2025), 93–108. https://doi.org/10.18400/tjce.1519835
  36. BS EN 16303:2020. Road restraint systems — Validation and verification process for the use of virtual testing in crash testing against vehicle restraint system. BSI Standards Publication, 2020.
  37. LSTC, 2019. A general-purpose dynamic finite element analysis program LS-DYNA version 971 user’s manual. Livermore Software Technology Corporation, Livermore, California, USA, 2019.
  38. Ozcanan, S., Atahan, A. O. 2019. RBF surrogate model and EN1317 collision safety-based optimization of two guardrails. Structural and Multidisciplinary Optimization, 60(1)(2019), 343–362. https://doi.org/10.1007/s00158-019-02203-z
  39. Ozcanan, S., Atahan, A. O. 2021. Minimization of accident severity index in concrete barrier designs using an ensemble of radial basis function metamodel-based optimization. Optimization and Engineering, 22(1)(2021), 485–519. https://doi.org/10.1007/s11081-020-09522-x
  40. NCAC. 2008. Finite Element Model Archive. George Washington University FHWA/NHTSA National Crash Analysis Center. http://www.ncac.gwu.edu/vml/models.html (Access date: 12.11.2008).
  41. CSI, (2017). Crash testing of H1 and H2 guardrails systems. 0021\ME\HRB\17, Bollate, Italy.