The primary aim of this investigation is to develop an analytical technique that can accurately estimate the fracture energy at the crack front while accounting for the localized interface properties. To achieve this goal, the study employs Double Cantilever Beam (DCB) specimens made of Aluminium alloys that have been chemically treated, as well as Titanium alloys that have been Laser texturized. Additionally, longitudinal defects are introduced within the bond line, specifically at the interface between the adhesive and adherents, with a parallel orientation to the crack direction. Initially, the investigation involved the characterization of bare surfaces, independent of their adhesive strength. Subsequently, Double Cantilever Beam (DCB) tests were conducted on specimens that had defects of various widths in the bonded region. The results obtained from these experiments confirmed the accuracy of the analytical estimations. It has been explained too that adhesive stiffness has a major role while mixing local fracture energies at crack front. Additionally, using a damage model, the deformation of the crack front was numerically observed and verified by capturing crack front shape while DCB testing. An interpretation was provided to explain the findings.

Today’s healthcare system relies on MRI (medical resonance imaging) for early diagnosis and treatment planning. For open MRI systems to achieve resolutions of about a hundred microns, a high voltage is required, as well as a specialized power supply. NP0 (Negative-Positive-Zero) ceramic is selected for the fabrication of adjustable capacitors. Specifically, it stands for which is a classification based on the temperature coefficient of capacitance (TCC) of the ceramic material used in the capacitor. NP0 capacitors have a TCC of 0 ±30 ppm/°C, which means that their capacitance value does not change significantly with temperature and frequency. They are known for their stability and low losses, making them ideal for applications that require high accuracy and reliability, such as timing circuits for RF applications. In this paper, MgTiO-CaTiO ceramic is used to make an adjustable capacitor with desired properties for MRI systems. To enhance the dielectric properties of MgTiO3 ceramics,CaTiO3 was added in varying concentrations. After pressing and sintering, the resulting samples were tested using a vector network analyzer in the frequency range of 10 MHz to 130 MHz.The adjustable capacitor fabricated using high co-fired NP0 ceramic may have been used for MRI applications such as tuning circuits and matching networks, where precise capacitance values and low loss are critical[1]. MRI systems with resonance frequencies of 128 MHz require trimmers with ceramic cores.