Pengaruh Temperatur Rendah pada Sifat Bending dari Pipa Komposit Epoxy dengan Penguatan Serat Jute

<p class="AbstractText">The experiment about the bending behavior of pipe composite based under the low-temperature treatment was carried out. As for the background of this research is that composite material become a suitable design with user need and it has behavior to substitute metal in engineering products. The research aims to investigate the effect of low temperature against to bending strength behavior of pipe from composite epoxy with jute fiber reinforcement. The low-temperature treatment was applied through an immersion process in dry ice as long as 60 minutes to produces a temperature of -33oC. The pipe composite was manufactured in lamination three layers of jute fabric using the vacuum injection molding process (VRTM). Then, the strength of the composite pipe was tested on the three-point bending method according to the ASTM D 790 standard. The testing results show that composite pipe with low-temperature treatment has a flexural strength average of about 76.559 MPa. Meanwhile, the compo-site pipe without treatment shows the strength of flexural average of about 52.435 MPa. They have the strength of flexural inclination is an average of 68%. In addition, the failures of composite in three-point bending test shows a shrank mode on the compression side and flat tearing at tension side due to the material becomes brittle. The conclusion that low-temperature treatment has an effective influence on the pipe composite mechanical properties.</p>

Full Generic Qualification of Nylon 12 Carbon Fiber Composite for Dynamic Thermoplastic Composite Pipe and Hybrid Flexible Pipe Applications

Composite structures are used as corrosion insensitive load bearing reinforcement in dynamic Thermoplastic Composite Pipe (TCP) and Hybrid Flexible Pipe (HFP) applications. The qualification of such structures can follow different strategies: product level versus material characterization. DNVGL-ST-F119 proposes a generic knowledge-based approach based on a testing pyramid. The pyramid allows a generic material characterization for a large number of conditions. Testing of dedicated specimens in constant media exposure measures the actual properties and changes of the material. Regression data is obtained for end-of-life properties. Simulations can be conducted using these properties to determine performance of the product in any state and condition and validate any load cases through classical stress combination. The characterization for VESTAPE® Nylon 12 Carbon Fiber thermoplastic composite (CF-PA12) covers all failure mechanisms for matrix, fiber and interface in static, dynamic and stress rupture mode for virgin, fully hydrocarbon saturated and aged to end of life in saturated condition. Each condition assessment is carried out in complete temperature dependency for subzero, room temperature, intermediate and maximum use temperature of 176°F (80°C). Fatigue testing covers runtimes of 106 cycles whereas stress rupture assessment exceeds 12,500h which corresponds to almost 1.5 years. With dense data populations for both regression curves and static test results the coefficient of variation is controlled. All characterization logic and data are analyzed for validity and certified by the official body of the DNV-GL. The material characterization enables simulation of a variety of application designs in predictive engineering and a simplified study is made for a dynamic gas injection jumper to demonstrate relevant occurring load cases. Utilizing all data and approaches allows to define the overall application envelope of the material. For the case of the thermoplastic composite of CF-PA12 it covers static flowlines, dynamic jumpers, service lines up to dynamic risers in sour crude service up to 176°F (80°C). The knowledge-based approach allows for economic design in engineering cases without compromising safety.

Corrosion Damage Behavior of X65/Incoloy 825 Welded Bimetallic Composite Pipe in H2S Environment

For the long-term service of X65/Incoloy 825 bimetallic composite pipe girth welds in the H2S environment, the corrosion damage behavior was investigated. Characterizations of welded joints were conducted by OM, SEM, XRD, and EDS. The pitting corrosion’s 3D surface morphology of welded joints in NACE-B solution saturated with H2S was investigated. The results show that composition segregation occurs in the welding process, and the Laves phase appears between dendrites, which lead to the decrease in corrosion resistance. The maximum depth of the corrosion pit is 2.46 μm after 30 days, 4.54 μm after 60 days, and 10.94 μm after 180 days. The cell automata (CA) model of corrosion damage was established based on the MATLAB program, and the basic elements of the cell automata model were determined. Through the simulation of the electrochemical reaction and diffusion process, the influence of different parameters of the pitting corrosion morphology was determined. The simulation results were compared with experimental data, which are available for the prediction of the morphology and size of the corrosion pits on the sample surface after 300 days. The results will be beneficial for the long-term service of the bimetallic composite pipe.