Wire Breakage Detection Using Relative Strain Variation in Unbonded Posttensioning Anchors

2015 ◽  
Vol 20 (1) ◽  
pp. 04014056 ◽  
Author(s):  
A. B. M. Abdullah ◽  
Jennifer A. Rice ◽  
H. R. Hamilton
Author(s):  
Yimin Xie ◽  
Jinbo Ning

Abstract Background/Purpose The Nuss procedure is the most common surgical repair for pectus excavatum (PE). Surgical steel wires are used in some modifications of the Nuss procedure to attach one or both ends of a support bar to the ribs. During follow-up, wire breakage was found in some cases. Patients with wire breakage may undergo prolonged bar removal surgery and may be exposed to excessive radiation.In this study, we had a series of patients who received polydioxanone suture (PDS) fixations instead of steel wires. This retrospective study was conducted to explore the differences between these two fixation materials in the incidence of related complications and efficacies. Furthermore, we attempted to observe whether the two materials lead to similar surgical efficacy in the Nuss procedure, whether they have divergent effects on the bar removal surgery, and whether PDS can reduce the risks due to steel wire breakage as expected. Methods We retrospectively studied PDS and surgical steel wires as fixation materials for the Nuss procedure in children with congenital PE and reviewed the outcomes and complications. A total of 75 children who had undergone Nuss procedure repairs and bar removals from January 2013 to December 2019 were recruited to participate in this study. They were divided into three groups: the PDS group, the unbroken wire (UBW) group, and the broken wire (BW) group, according to the fixation materials and whether the wires had broken or not. Moreover, we selected the duration of operation (DO), intraoperative blood loss (BL), bar displacement (BD), postoperative pain score (PPS), and incision infection as the risk indicators and the postrepair Haller index (HI) as the effectiveness indicator. These indicators were statistically compared to determine whether there were differences among the three groups. Results One BD occurred in the PDS and BW groups while none took place in the UBW group. No incision infection was found in any of the groups. The PDS group had the shortest DO, while the DO in the UBW group was shorter than that in the BW group (p < 0.05). BL in the PDS group was less than that in the other two groups (p < 0.05). Additionally, no difference was observed in BL between the BW and UBW groups (p > 0.05). The PPS of the PDS group was less than that of the BW group (p < 0.05), whereas no differences were found between the other two groups. No statistical difference emerged in HI among the groups (p > 0.05). Conclusion PDS fixation results in a similar repair outcome and shows certain advantages in the DO, BL, and PPS; also, PDSs are safe and effective in the Nuss procedure. Level of evidence Level III.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Kejie Zhai ◽  
Hongyuan Fang ◽  
Bing Fu ◽  
Fuming Wang ◽  
Benyue Hu

Prestressed concrete cylinder pipe (PCCP) is widely used for long-distance water pipelines throughout the world. However, prestressing wire breakage is the most common form of PCCP damage. For some pipelines that cannot be shut down, a new technique for in-service PCCP repair by externally bonding the pipe with layers of carbon fiber reinforced polymer (CFRP) was proposed. A set of three-dimensional finite element models of the repaired PCCP have been proposed and implemented in the ABAQUS software, which took into account the soil pressure, the weight of the PCCP, the weight of the water, and the hydrostatic pressure. The stress–strain features of the PCCP repaired with CFRP of various thicknesses were analyzed. The stress–strain features of different wire breakage rates for the repaired PCCP were also analyzed. The results showed that the strains and stresses decreased at the springline if the PCCP was repaired with CFRP, which improved the operation of the PCCP. It has been found that the wire breakage rates had a significant effect on the strains and stresses of each PCCP component, but CFRP failed to reach its potential tensile strength when other materials were broken.


Author(s):  
A A Safitri ◽  
I Meilano ◽  
E Gunawan ◽  
H Z Abidin ◽  
J Efendi ◽  
...  

Author(s):  
J. Groenendijk ◽  
C. H. Vogelzang ◽  
A. A. A. Molenaar ◽  
B. R. Mante ◽  
L. J. M. Dohmen

The relative strain effects of 15 different load configurations were studied. Using the linear tracking device (LINTRACK) accelerated loading facility, two 5-year-old pavements of 0.15-m asphalt on sand (one virgin and one loaded with 4 million 75-kN wheel loads) were tested. All measured strains were converted to strain factors relative to a standard load (super-single tire, 50 kN, 0.70 MPa). The results were compared with earlier measurements and BISAR-calculated factors. The results on the loaded pavement showed markedly more variation than those on the unloaded pavement. Generally, the BISAR-calculated relative strain factors matched the measured values well for the super-single tire. Considerable difference occurred only in the most extreme load conditions. Nonuniform contact stress distribution can be the cause for this. The calculated relative strain factors for the dual tire configurations underestimated the measured values.


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