## 1 Introduction  
A bonded joint is a permanent connection formed by connecting two or more parts together with an adhesive layer [1; 2]. Metallic adhesives are used to bond two or more metal surfaces strongly and flexibly enough to resist separation, without the need for traditional methods such as nails or screws. These adhesives are natural or synthetic substances [3; 4; 5; 6]. Adhesion has made progress with the development of material technology [7]. The use of adhesive in carrier structures, time and cost savings, high corrosion and fatigue resistance, cracking delay, excellent damping properties and other properties has made it an important player in the aerospace and automotive, wood, and plastic industries [8; 9; 10; 11]. The usage needs of different materials together has also improved joining techniques and versatility [12]. However, in many applications that require structural durability, combining with adhesive is preferred. Such joints are especially common in the aerospace and automotive industries [13; 14; 15]. Adhesive joints have a great impact on making designed systems lighter, stronger, and more economical. Adhesivebonding has more advantages than mechanical bonding [16; 17]. These include the ability to combine different thicknesses and types of materials, create joints with equal load distribution, and include the ability to function as a seal [18]. The holes, notches, etc., can also be applied to the surface. It is a cost-effective, simple and fast solution because no joint details or precision machining tolerances are required [19; 20; 21]. Despite all these factors, adhesive bonds also have disadvantages. Good adhesion requires proper surface preparation, proper adhesive selection and a suitable environment [8; 22]. The strength of such joints is affected by factors such as the surface treatment, material type, adhesive thickness, ambient temperature, and type of load. However, exposure to environmental conditions causes aging over time due to changes in its chemical structure [23]. Due to the properties above, the bond forces and the factors affecting them have been discussed by many researchers. Adhesive bonding is inexpensive, does not cause crystal structure changes on melting, such as welding, riveting and other types of bonding, does not generate voltage concentrations, and bonds under melting temperatures, resulting in smoother bonding [24; 25; 26]. The types of adhesives developed with the use of adhesives have been increasing. In addition, adhesive research continues and people want to benefit from it in every field. Due to the lightness of magnesium alloys, the specific tensile strength is higher than that of aluminum and steel. Due to the low density of magnesium, it appears to have higher specific strength than aluminum, plastic composite materials, and steels [27; 28; 29]. Therefore, magnesium alloys are widely used in the automotive, electronics, defense, and aerospace industries today [30]. In recent years, the use of magnesium alloys in the automotive and aircraft industries has been predicted to increase significantly. Mg-Al-Zn (AZ91) alloy is mostly used for casting automotive and aircraft parts due to its light weight [27; 31; 32; 33]. AZ91, a magnesium alloy is better at casting properties and better at yielding strength properties than other magnesium alloys. From engines to chassis, the magnesium alloys are used in every part of cars [28; 34; 35; 36]. In [PERSON]'s 2005 study, he examined using a three-dimensional finite element model that included the effects of load distribution, bolt hole contact, and nonlinear material behavior of the hybrid composite single lap joints. He examined the derail and finite element analysis comparatively and it showed that the hybrid joint showed structurally more advanced performance than adhesive bonding and he produced some harmonious results [37]. [PERSON] and [PERSON] used the finite element method in 2006 to eliminate the damage to the adhesive-reinforced gear joint and to ensure this.