# Pipe Subjected to Internal Pressure

This analysis example shows consideration of improved compressive strength design for pipe subjected to internal pressure.

## Previous Method

Usually, in cases such as when a pipe is subjected to internal pressure, cracking occurs in the axial direction under applied circumferential pressure. Thereby, a method of adding additional reinforcing ribs by adding parts in the circumferential direction such as in the following model will be considered when you design with improved compressive strength.

## The Present Case Method

Performing a study of material design for satisfying the pressure resistance using composite material, without the reinforcing ring or ribs.

This time, we conducted the structural design and micro material design at the same time for textile composite material (Figure 1) and stitch composite material of ±55 ° (Figure 2).

 Figure 1: Textile Composite Material Figure 2: Stitch Composite Material

### Step 1: Homogenization Analysis

Calculate the equivalent physical properties of composite material (microstructure) by numerical material test using homogenization method.

Structural analysis: Elastic modulus, Shear elastic modulus, Young's modulus, Poisson's ratio
Heat transfer analysis: Thermal conductivity

### Step 2: Macro Structural Analysis

Performing the macro structural analysis applying the equivalent property value obtained from homogenization analysis as material characteristics of macro structural.

### Step 3: Localization Analysis

Solving localized results by micro structural analysis specifying an arbitrary area from the results of macro structural analysis.

### Step 4: Micro Model Evaluation

All fibers in stitch composite material of ± 55 ° vertical and horizontal have assigned uniform stress. All fibers in textile composite material of 0 ° + 90 ° have assigned stress with a 1:2 ratio. As a result, it can be said that stitch composite material of ± 55 ° is very effective in the design of structural elements subjected to pressure.

 Stress occurring in textile composite material of 0 ° + 90 ° Stress occurring in stitch composite material of ± 55 °

## Data Provided

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