Re: Kleinlogel Rigid Frame Formulas
Rocki Stenger
Kleinlogel Rigid Frame Formulas
A rigid frame is a structural system composed of beams and columns that are rigidly connected to each other, forming a stable and rigid structure. Rigid frames are commonly used in buildings, bridges, and other structures that require resistance to lateral loads, such as wind and earthquake.
However, analyzing a rigid frame is not a simple task, as it involves solving a system of simultaneous equations that account for the internal forces and moments in each member and joint. To simplify this process, some engineers use empirical formulas that provide approximate solutions for common types of rigid frames. One of the most well-known sources of these formulas is the book "Rigid Frame Formulas" by Alfredo Kleinlogel, published in 1964.
Kleinlogel's book contains formulas for various types of rigid frames, such as fixed-base, pinned-base, portal, gable, and multi-span frames. The formulas are derived from the principle of virtual work and the method of least work. The book also provides tables of coefficients and graphs that can be used to calculate the internal forces and moments in each member and joint.
The advantage of using Kleinlogel's formulas is that they are easy to apply and do not require complex calculations or computer software. The formulas can also be used for preliminary design and optimization of rigid frames. However, the formulas have some limitations and assumptions, such as:
- The frames are statically determinate or have a known degree of redundancy.
- The frames are subjected to uniform loads or concentrated loads at the joints.
- The frames have constant cross-sections and material properties.
- The frames have small deflections and linear elastic behavior.
- The frames have symmetrical geometry and loading.
Therefore, the results obtained from Kleinlogel's formulas should be verified by more accurate methods, such as the stiffness method or the finite element method. Moreover, the formulas may not be applicable for complex or irregular frames that do not fit the assumptions or the types covered by the book.
In conclusion, Kleinlogel's rigid frame formulas are a useful tool for engineers who need to analyze simple or common types of rigid frames quickly and easily. However, the formulas are not a substitute for more rigorous methods of analysis that can account for the actual behavior and characteristics of the frames.
For more information on Kleinlogel's rigid frame formulas, you can refer to the following sources:
- [Rigid Frame Formulae - YourSpreadsheets]
- [Engineering.com]
- [Kleinlogel Rigid Frame - help.environment.harvard.edu]