Issue 67

S. S. E. Ahmad et al., Frattura ed Integrità Strutturale, 67 (2024) 24-42; DOI: 10.3221/IGF-ESIS.67.03

Figure 18: Experimental and numerical K 1C against a/d for specimens’ width b = 120 and 250 mm.

Comparison between experimental and numerical K 1c Experimental data and numerical methods provide insights into material behavior. Numerical simulations allow for parametric studies of complex scenarios, while experimental testing validates real-world conditions. Combined, these approaches provide a comprehensive understanding of material behavior. In this section, a comparison between the obtained results of experimental and numerical K 1C was given. Fig. 18 presents the correlation between a/d and K 1C for b values of 120 and 250 mm numerically and experimentally. The results exhibit that the behavior of K 1C , both experimentally and numerically, is quite similar. It is observed that with an increase in a/d and b , K 1C also increases. In the case where b = 120 mm, the K 1C numerical results exceeded the experimental results for all a/d values, with differences of roughly 8%, 45%, and 7% for a/d values of 0.1, 0.2, and 0.3, respectively. On the other hand, in the case where b = 250 mm, K 1C numerical results were consistently lower than experimental results for all a/d values. Differences were approximately 24%, 20%, and 4% for a/d values of 0.1, 0.2, and 0.3, respectively. One can notice a remarkable decrease in the difference between experimental and numerical results, especially with increasing in a/d . 2- The K 1C is affected by the a/d , and it has been observed that an increase in the a/d from 0.1 to 0.2 for a beam width of 120 mm results in a 0.98% and 39.22% increase in the K 1C . Similarly, an increase in the a/d from 0.2 to 0.3 for the same beam width results in a 46% and 84.67% increase in K 1C . 3- When a crack is present, stress tends to concentrate at its tip, causing a reduction in the total number of cracks that will occur. 4- When the a/d increases, the impact of steel reinforcement also increases due to the increased moment arm from the centroid of the steel to the crack tip. 5- There is a remarkable decrease in the difference between experimental and numerical results, especially with increasing in a/d . T C ONCLUSIONS his study examined 8 reinforced concrete beams with different crack depths and widths. Both experimental and numerical methods were used. The study found certain conclusions. 1- The K 1C is influenced by the width of the specimen. When the beam width is increased from 120 mm to 250 mm, there is an experimental increase of approximately 46% and 84.67% and a numerical increase of about 53.98% and 134.51%.

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