The effects of internal pressure are described in detail in Effects of Internal Pressure above. The axial bending stress component
σn,b is always positive due to the assumption that the gauge pressure is positive. In reality, it represents a bending stress, so the true sign differs between the inside and the outside of the pipe.
The effects of thermal expansion are described in detail in Effects of Thermal Expansion above. The axial bending stress component
σt,b is always positive due its definition. In reality, it represents a bending stress, so the true sign differs between the inside and the outside of the pipe.
If the true distributions of σn,b and
σt,b have opposite signs, this will be conservative.
where do is the outer diameter. This value replaces the stress from the stress evaluation points (
σbk) in maximum stress expressions, thus ensuring that the correct peak stress is evaluated irrespective of where it appears along the circumference.
where γm and
γb are defined in
Effects of Internal Pressure. The bending part is defined as positive. In reality, it represents a bending stress, so the true sign differs between the inside and the outside of the pipe. Under the assumption of a positive gauge pressure, the positive sum will however exist on either the inner or the outer boundary.
where Wt is the torsional section modulus. This result is available only in 3D.
where Tlz is available only in 3D. In the case of Timoshenko theory shear force is computed directly from the shear strain.