In tire industry, it is very crucial to evaluate physical and mechanical properties of rubbers which are used for production of tires, to ensure the quality of the final product. Resilience is an important property of a rubber, which cannot be evaluated through direct measurement in production cycle in this industry. Therefore, Non-Destructive Ultrasonic Testing, which has been used in many applications for examination of various material properties, can be used as an alternative approach for this purposes. In this study, the Non-Destructive Ultrasonic Testing method has been employed to investigate the resilience of nanoclay reinforced rubber compounds. By changing physical and mechanical properties of materials, Ultrasonic wave velocities are changed. For this purpose, sixteen different samples of nanoclay reinforced rubber compounds with different formulations were prepared and both their resilience and the longitudinal Ultrasonic wave velocity through them were measured. In the next step, using the relevance vector machine regression analysis, a mathematical expression for the rubber resilience based on the longitudinal Ultrasonic wave velocity was developed, which was proven to be qualified with acceptable accuracy and generalization capability. The results of this research can be used for online evaluation of the rubber resilience in tire production cycle.

In this laboratory study, a mixing design was made of ordinary concrete containing Portland cement with a grade of 500 kg/m 3 and a mixing design was made of alkaline concrete based on slag from the composing furnace. To investigate the mechanical properties, a nondestructive test was performed to determine the velocity of Ultrasonic vibrations in concrete at 21 and 600 °, C at a 90-day curing age. In order to evaluate the microstructure of theconcrete and verify the results of Ultrasonic test, compressive strength test and scanning electron microscopy imaging was performed on concrete samples. The results showed a decrease in the speed of Ultrasonic vibrations after applying high temperature (600 °, C) in concrete, so that in ordinary concrete and hard concrete, the deceleration rate was 44. 79% and 40. 58% in the results after and before, respectively. In this regard, the velocity of Ultrasonic waves in ferrous concrete were lower than ordinary concrete, so that at 21 and 600°, C, the percentage of velocity drop in ferrous concrete compared to conventional concrete was equal to 10. 48 and 3. 66%, respectively. The results of the compressive strength test and the images obtained from the scanning electron microscope were in good agreement with the results of the Ultrasonic tests in concrete at 21 and 600°, C.

In last two decades, a considerable enhacement in developing and using of nondestructive techniques in the field of agriculture yields quality-metering is achived. Ultrasonic test, as a nondestructive test method, is being developed in agriculture yields quality-metering. Among native fruits, tomato, for many reasons have a special place, but main studies about damages to its texture have not been conducted. For this reasons, tomato was selected for this study. In this study, Ultrasonic Quali-Meter System (UQS) is utilized to investigate the texture and other sougth properties of tomatos by sending and receiving the ultrasound waves through the tomatos. UQS by sending and receiving non-continuous signals determines Ultrasonic indexes such as velocity of waves passing through tomatos, attenuation coefficient and so on. In this study, 360 ripe early tomato (first tomato) samples of Khuzestan province were made available and prepared for the tests. The tomatoes are divided into four groups of 90 units each. Out of these groups, the fourth group was selected as the instance group, on which loading it is not performed. The other three groups were exposed to traumatic loading by free drop test method at three energy levels of 0. 8, 1 and 1. 2 J. . Every day, out of each group, 9 samples were randomly selected and surveyed for the Ultrasonic, biochemical, mechanical and physical indices. Results showed that tomato damage level and storage time have meaningful effect on Ultrasonic wave velocity and stiffness. Hence, use of the Ultrasonic method provides the possibility of determination and estimation of some parameters related to tomato ripening in supplying lines such as separating operation and fruit grading.

Resistance spot welding process is one of the most common and oldest methods of resistance welding. It is widely used in various industries, especially automotive, aerospace, electronics and nuclear industries. In a car body, there are approximately 2000 to 5000 spot welds. Spot welding quality control is carried out according to international standards, which is often accompanied by demolition of samples. The use of a destructive method in controlling the quality of spot welds on different parts or the entire body of the car costs a lot. Nondestructive quality control of spot welds will reduce these costs. One of these nondestructive methods is an Ultrasonic Testing that has been successfully used in this project. The Ultrasonic waves measure the diameter of the nugget, which is an important indicator of weld quality. In this study, a large number of intact and defective spot welds were prepared and tested by Ultrasonic nondestructive methods and pull-shear destructive Testing. The results of these experiments showed that the Ultrasonic tests can successfully detect defective welds.

An Ultrasonic transducer (probe) is an important part of an Ultrasonic Testing system. It comprises of a piezoelectric disk, backing material and matching layer. The process of selection and design of these components for any specific Ultrasonic transducer is a challenging task. The backing material should be able to attenuate the Ultrasonic waves and to reduce the ringing time of the piezoelectric disk. In this paper, a combination of metal particle (tungsten) and epoxy resin is used as backing material in fabricating transducers. The results show that the performance of the Ultrasonic transducer is highly dependent on the characteristics of the backing material constituents. A high resolution or a high energy transducer can be produced just by changing the backing material.

Heat treatment and production methods such as rolling, forging, deep drawing, etc, induce residual stresses as well as texture changes in the billets. T1zese processes cause the billets to become anisotropic. In "Acoustoelasticity", residual stresses can not be determined unless the texture is already mown apriori or determined simultaneously. In the present article, the equations of particle motion in an anisotropic elastic medium in the presence of residual stresses and texture is considered for two cases of rolling processes. Using elastic wave propagation in the medium, the relationships between the wave velocity and the residual strains as well as texture parameters in special planes are obtained for the general case and then simplified for rolled billets. The residual stress effects on the wave velocities are also discriminated from the effects of texture. The analytical results are discussed and compared with the experimental results for the case of one-dimensional stresses in billets, showing good agreement.

The Ultrasonic wave velocity was used to detect decay extent and depth. An oak block (15x20x30 cm) with local decay was inspected in three main directions (longitudinal, radial and tangential). Ultrasonic wave velocities in three axis of decayed oak were incorporated into contour and color gradient plots along the wood profile for three direction inspections using Sigma Plot software. The specimen was dissected to compare the predicted internal condition to the actual internal condition. The results showed that the predicted internal condition by Ultrasonic technique is in good agreement with the actual internal condition D. ecreasing of Ultrasonic wave velocity depends on depth and different stages of decay.

Thermography is one of the new, fast and low-cost methods for nondestructive Testing. In this method, the workpiece is subjected to heating under the modulated heat source, and the images of the process are stored by the thermal camera. In this research, the feasibility of this method was performed on a plastic cutter. The results showed that deeper and smaller defects are better identified in the image of the amplitude of the heat wave amplitude. It was also found that the quality of phase images is higher than the image of the domain and is less affected by the test conditions, such as asymmetric heating and light reflection. By optimizing the test conditions, the defects can be displayed with the use of domain images. Also, two different frequencies with a relatively high spacing of 0. 5 Hz and 1 Hz were used to obtain a suitable frequency for the workpiece. Due to the appropriate heat transfer, lower frequency use in the test is recommended to provide a more appropriate time interval for detecting defects.