The crack growth behavior of fiber metal laminates (FMLs) with fiber orientations of 90°/0° and 45°/45° to load direction was investigated with varying stress ratios of the cyclic constant load. The study shows that crack growth behavior depends on the conditions of the cyclic load and the orientation of the fiberglass orientation. A higher stress ratio of the cyclic constant load causes fatigue life to decrease, and is associated with stress concentration just in front of the crack tip. The stress concentration in the FMLs with 45 o /45 o fiberglass orientation is higher than that of 90 o /0 o , which means the fatigue life in the former is shorter. The bridging of the fiberepoxy composite takes place when the stress ratio of the constant cyclic load is lower than 0.4, which also enhances fatigue life.

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This study aims to find material steel for animal feed chopper machine which is not easily corroded with method of hot dip galvanizing (HDG). Steel as machinery components or construction often gets broken before the predicted time because of corrosion. The HDG method was begun by pre-treatment process which were polishing, degreasing, rinsing I, pickling, rinsing II, fluxing, and drying. The main process of galvanizing was done by dipping in 98% of zinc solution with temperature variation of 430, 450, 470, and 490°C. The coating thickness measurement was run with Coating thickness NOVOTEST TP-1M. The corrosion was tested with electrochemical method of potentiodynamic polarization with AUTOLAB PGSTAT 128. The highest value of coating thickness was at galvanized temperature of 490°C which was 88.9 ± 3.24%. The value of standard deviation was indicated by how much the coating homogeneity formed. This was in line with the amount of corrosion rate at galvanized temperature of 490°C. The highest corrosion rate values in H2SO4 and NaCl environment were 1.18 and 0.21 mm/year. The highest hardness value of Zn layer is galvanizing temperature of 490°C which rises 41.71% of the base metal. The coating thickness, corrosion and surface hardness test have thee good agreement.

Epoxy adhesive has been used widely in automotive and aircraft industry because it has the characteristics of a good joint in the structure of the component. The addition of the powder material on epoxy adhesive affect to the crack propagation behavior on the joint. It also affects to the peel and shear strength of the joint. A real experimental study of peeling and tearing test was used in this study. It aims to determine the effect of the type of powder material on crack propagation behavior and also peel and shear strength of the adhesive joint. The independent variable of this study is without powder and with powders (aluminum, iron ore, silica). The dependent variable is the crack propagation behavior and peel and shear strength. The results of the investigation shown that the addition of powder material either metal or non-metal on the epoxy adhesive joint affect on the maximum force and the displacement. In addition, it can also increase the peel and shear strength. In the peeling test, mixture of adhesive and cohesive fracture was occurred. And in the tearing test, fracture adhesive was dominated.