Abstract
This paper is a study of the application of iron-base needles on brittle fracture cracks. Brittle fracture is a major challenge that needs to be solved in order to ensure the performance and life of engineering materials. Iron-base needle technology is one of the potential methods for brittle fracture cracking treatment, which has gained extensive attention in recent years. In this study, the concept and application of the technology are presented. Methods such as finite element analysis and experimental tests were conducted to investigate the effects of the application. In addition, finite element analysis was used to investigate the stress distribution of the needle bodies before and after application in order to ascertain their efficacy as anti-crack products.
Introduction
Brittle fracture, also known as fracture’, is defined as the fracture of materials due to their inherent ductile properties, which are affected by the environment, loading and temperature. Due to the inhomogeneity of engineering components, brittle fractures can occur at random locations on the surface of the component. As a result, brittle fracture has become a major enigma in many engineering fields, and its repair and prevention is one of the major concerns of researchers. As the traditional methods such as welding and/or post welding heat treatment are usually expensive, time-consuming and require a high level of skill, alternative methods are being developed. One of the methods being developed is the application of small iron-base needles, which can reduce the cracks by providing additional local structural stability.
Concept and Application of Iron-Base Needles
The concept and application of iron-base needles is relatively simple. The needles consist of small-diameter iron-base tubes that are inserted into a crack in order to stabilize the crack faces and reduce the associated stresses and strains. By providing additional stability and support to the crack, the occurrence of further cracking is inhibited. In addition, iron-base needles act as a form of reinforcement, which helps to reduce the likelihood of further cracking along the same line.
In order to reduce the risk of further cracking, the needles should be arranged in the same direction of the crack. This allows the needles to resist the tensile forces across the fracture surface. Furthermore, the needles can be arranged in a staggered arrangement so that the needles will provide extra reinforcement of the crack face.
Finite Element Analysis and Experimental Tests
In order to further investigate the efficacy of iron-base needles as an anti-crack treatment, a finite element analysis (FEA) and an experimental test were conducted. The experimental test was a bending test, which was conducted on an aluminum alloy material with pre-induced notch to simulate a brittle fracture crack. The material was subjected to a three-point bending force at the notch and the performance was assessed based on the crack growth behavior under cyclic loading.
The FEA, on the other hand, was conducted using ANSYS, a general-purpose finite element analysis software. The analysis was conducted on a two-dimensional simulation model with a pre-induced simulated notch. The model was subjected to a bending force and the effects of the application of iron-base needles on the stress distribution in the notch were observed.
Results and Discussion
The results of the bending test showed that with the application of iron-base needles, the micro-cracks were effectively inhibited and the durability of the material was enhanced. In addition, the results of the FEA also showed that the needles contributed to reducing the stress concentration along the notch. Furthermore, the FEA also showed that upon the application of the needles, the stress distribution at the notch changed, which indicated the efficacy of the needles in relieving the stress concentration at the notch.
Conclusion
In conclusion, iron-base needle technology has potential as an effective method to reduce and prevent brittle fracture cracking. The application of the iron-base needles showed to be effective in reducing micro-cracks and in relieving the stress concentration at the notch. Furthermore, finite element analysis revealed that the iron-base needles can also contribute to a more uniform stress distribution along the notch. This paper thus presented a brief overview of the concept of and methods for applying iron-base needles. Nevertheless, further research is necessary to validate the efficacy of the technique.
