Development of the modified clothoidal (MCL) shape of composite dowels against the background of fatigue and technological issues
oraz
08 kwi 2024
O artykule
Kategoria artykułu: Original Study
Data publikacji: 08 kwi 2024
Zakres stron: 91 - 110
Otrzymano: 28 wrz 2023
Przyjęty: 01 mar 2024
DOI: https://doi.org/10.2478/sgem-2024-0005
Słowa kluczowe
© 2024 Wojciech Lorenc et al., published by Sciendo
This work is licensed under the Creative Commons Attribution 4.0 International License.
Figure 1:

Figure 2:
![Results of push-out tests conducted by UBWM [7]: force per dowel versus relative slip for the SA, PZ, and CL shapes (the horizontal axis shows the slip displacement measured in the tests).](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_002.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=7fcbb8a9e6313db6aea79677156da6148038f0aa440cdce5a4555e0b5f9ef267&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 3:
![Cutting technology for production of test specimens for project [7]: a) and b) single cutting line for the PZ and SA shapes and c) two cutting lines for the CL shape.](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_003.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=ec2606287e2c4a2613f653269ceb8bffc1735a2535b5bc75ad07704a0bdb6ec2&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 4:
![The idea of the new push-out-test (NPOT) specimen proposed by the author to be used for cyclic tests [7] (2 million cycles).](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_004.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=cb8eaf847f02bd4091840995712f4de4cd12ca02b375a8d1b75730b6b474bd28&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 5:

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Figure 7:

Figure 8:

Figure 9:

Figure 10:
![Documentation of fatigue cracks in the NPOT-PZ2 specimen tested in of the PreCo-Beam project [7]: a–f) view after cutting the concrete part, g) general view of the crack, h) beginning of the crack, and i) end of the crack](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_010.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=6943db9f0464715efce613f2a4260488cb00623772ef85b79069d9cd539ba705&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 11:
![The original concept of dimensionless resistance of steel dowels regarding local and global effects [5,6] (Fig. 13d in [6]): fatigue coefficients for tension stress for PZ shape (at the left; to be compared with Fig. 20 and [22] for the clothoidal shape) and general prediction for complete stress set (at the right).](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_011.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=8712fa8020e0acd0f1b5fa82603531a4323632271913bbe84e05f68fc4149d44&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 12:
![Strain gauges on NPOT specimens with CL shapes for purposes of [7].](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_012.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=46b90bf9f64d3de11323423f17f6c93015f76898953b09286b701cb0369955ca&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 13:

Figure 14:
![Summary of characteristics of the basic shapes highlighting the problems with the idea of a new cutting line and the basis standing behind this idea (original drawing of steel parts of NPOT specimens for discussions with partners of the PreCo-Beam [7] project: only the SA and PZ shapes were used in bridges before construction of the “Wierna Rzeka” Bridge in Poland [62]).](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_014.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=ca8b173053c5a3fd19ad494cf44afecccede48a3212f50f829c9e16b68492f89&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
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Figure 19:
![Results of the numerical simulations of the MCL 115/250 shape (the shape after optimization of the ratio according to the procedure presented in Fig. 30 in [57]) by Abaqus software.](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_019.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=16330d7c3d33d1ecff718eba51993ffdb5966a060ec6446aa1b438a4307d1d43&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 20:
![Dimensionless stress concentration factors (according to [5,6]) for the MCL 115/250 shape and the PZ 300/100 shape.](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_020.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=deb162d46222ea7d1b2c61ad2c656c76e94486bd6fc0c18406c8f420a318808d&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 21:

Figure 22:
![Different shapes and technologies of production of steel dowels with the clothoidal shape: a and b) different shapes of the “nose” of steel dowels by different producers fabricated in Poland out of plates by oxy-cutting, c) small dowels fabricated in Luxembourg by plasma cutting, d) elements of the PE4 bridge design by the author in Poland [12] fabricated in Luxembourg by oxy-cutting and plasma cutting, and e) steel elements of the PE4 bridge at the construction site (a large number of elements were produced with the MCL 115/250 shape).](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_022.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=9a0bc46bfd3bc9d8e34ab4d9573ce52a71150f0c816930cca14b4aa9f1f9bfd1&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 23:

Figure 24:

Figure 25:
![Implementation of composite dowels in innovative composite bridges in Poland: a) and b) implementation in beams – bridge in Elbląg (presented in [41]) and c) implementation in arches – a new solution as part of a network arch bridge using composite dowels [63].](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_025.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=3394430816d470f5808395d73088f52616e6f6d3b301013e1d33275e38d1277a&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 26:
![Nominal geometry of the modified clothoidal shape of a single connector MCL 100/250 according to [16] given as a function of the spacing of connectors ex.](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64737a3e4e662f30ba53f8da/j_sgem-2024-0005_fig_026.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250911%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250911T112106Z&X-Amz-Expires=3600&X-Amz-Signature=a53affb644bdd97687e1eb63fad9e9eee78efe0109ef2081b366dc800dc07e53&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Main stress values (MPa) in the NPOT models estimated using FEA for coarse mesh density – the stress level is given at the minimum (σP = 120 kN) and maximum (σP = 280 kN) load level and their difference (ΔσP = 160 kN)_
CL | 132.0 | 176.0 | 308.0 |
SA | 134.6 | 179.4 | 314.0 |
PZ | 157.6 | 210.2 | 367.8 |