Blog Posts Tagged Structural Mechanics Module
Fatigue Prediction Using Critical Plane Methods
Research on fatigue started in the 19th century, initiated following failing railroad axles that caused train accidents. In a rotating axle, stress varies from tension to compression and back to tension in one revolution. The load history is simple because it is uniaxial and proportional. Fatigue can then be evaluated with the S-N curve, also known as the Wöhler curve, which relates stress amplitude to a component’s life. In many applications we deal with multiaxiality and non-proportional loading. In this […]
Simulating an Engine Governor, the Spring Loaded Centrifugal Governor
We’ve probably all seen centrifugal force in action in one way or another, whether it be riding on a merry-go-round as a child, spinning a bucket of water upside and observing as the contents hug the insides of the bucket, or watching mud spinning off of a turning tire. In addition to making dizzying carnival rides, this force can be used in the design of many mechanical applications, where it is harnessed to control a variety of effects. One such […]
Aircraft Landing Gear Mechanism Analysis
Aircraft rely on landing gear in order to taxi, take off, and land. The landing gear of your average commercial airplane consists of a shock-absorber cylinder and piston, and a pair of tires. Intuitively, the shock-absorber experiences stresses as the landing gear touches the ground — but how much? In order to design a landing gear mechanism that can withstand many landings, and to determine when it’s time to swap out an old one, we can perform a multibody dynamics […]
Random Load Fatigue
In many applications, loads applied to structures are random in nature. The sampling results of the structural response will differ depending on the data collection time. Although the stress experienced is not always high, the repeated loading and unloading can lead to fatigue. The engineering challenges in these types of applications are defining the stress response to the random load history in the critical points, and predicting fatigue damage. This is simulated with the Cumulative Damage feature in the Fatigue […]
Double Pendulum Simulation Tutorial
Dynamic simulation of a double pendulum system can easily be performed using the Multibody Dynamics Module available in COMSOL Multiphysics. This module enables the mechanical simulations of assemblies of flexible and rigid bodies, often coupled with other phenomena such as from heat, electrical, and others.
Simulate Mechanical Systems with the Multibody Dynamics Module
The new Multibody Dynamics Module provides engineers with an advanced set of tools to design and optimize mechanical systems to reduce product development costs. This module enables simulation of an assembly of flexible and rigid bodies, along with physical phenomena like structural, heat, electrical, and others. One of the key capabilities included in this module is an easier and faster way of building connections between different bodies using various types of predefined Joints. The objective of multibody analysis is to […]
Multibody Dynamics
The dynamic analysis of interconnected bodies or links is called a multibody analysis. These bodies are connected by joints that constrain their relative motion. The simplest element of a multibody system is a single particle, which can be considered using Newton’s laws of motion. Multibody Dynamics has a long and storied background.
Barrel Hinge Analysis
We’ve all encountered hinges before; they are frequently used to connect different parts of mechanical assemblies in a way that allows them to move freely relative to one another, in a single degree of freedom. There are several different types of hinges, including everything from barrel hinges to friction hinges, with lots in between. Before incorporating a hinge into a mechanical assembly, you might want to get a sense of how it will hold up by performing a hinge analysis.