What is effective mass participation factor?

“The effective mass participation factor represents the percentage of the system mass that participates in a particular mode. It provides a measure of the energy contained within each resonant mode. A mode with a large EMPF is usually a significant contributor to the dynamic response of a system.”

What is modal mass participation factor?

The modal participation factor is a measure of how strongly a given mode contributes to the response of the structure when subjected to force/displacement excitation in a specific direction. In this case, the load amplifies the mode and large displacements can result.

What is effective mass in modal analysis?

The effective modal mass provides a method for judging the “significance” of a vibration mode. Modes with relatively high effective masses can be readily excited by base excitation. Perhaps the number should be enough so that the total effective modal mass of the model is at least 90\% of the actual mass.

How do you increase modal mass participation ratio?

Increase the Number of Modes The simplest and most direct way to improve mass participation is by increasing the number of modes used in the dynamic analysis. Doing so will also increase the overall time it takes to complete the dynamic solution.

How do you increase mass participation factor in staad?

Abhishek_Singh

1. Check the loading. Load contribution is very essential in mass participation.
2. Try to increase the size of columns a little bit.
3. Generally the number of modes to be extracted should be minimum 3X number of floors in the building.
4. Check the load combination used to find out the lumped mass.

What is electron effective mass?

The effective mass is a quantity that is used to simplify band structures by modeling the behavior of a free particle with that mass. For electrons or electron holes in a solid, the effective mass is usually stated in units of the rest mass of an electron, me (9.11×10−31 kg).

What is effective mass in vibration?

The effective mass offers a physical interpretation of a physical system with multiple modes of vibration being excited dynamically from a base, similar to testing that occurs for many systems. The concept was proposed in the early 70’s by Bamford[1] with others.

What is the example of mass participation?

A sporting event in which many people participate. Often, participants are spread out over several miles in variable terrain. Injury rates in mass participation events increase with increased distance and environmental temperature.

Why effective mass of hole is greater than electron?

The effective mass is a result of electron interaction with lattice, i.e. with phonons. As the hole velocity is smaller, a hole spends more time in the interaction region, i.e. holes strongly interact with phonons. This leads to larger effective mass.

What is effective mass obtain the expression for effective mass of electron?

This mass of an electron is called the effective mass of an electron, denoted as m*. The effective mass is thus determined by d 2E/dK 2.