In this post, we are going to analyze the stress and deformation of a rubber O ring as shown in the following figure. The rubber O ring is often used for sealing purposes. It may be under large pressure and its deformation is constrained by the sealing groove. Due to the large difference in the … Continue reading The stress and deformation analysis of a rubber O ring
Harmonic analysis: A steel disk example
Harmonic analysis is used to determine the steady-state response of a linear structure to loads that vary sinusoidally (harmonically) with time, thus enabling you to verify whether or not your designs will successfully overcome resonance, fatigue, and other harmful effects of forced vibrations. This analysis technique calculates only the steady-state, forced vibrations of a structure. … Continue reading Harmonic analysis: A steel disk example
Examples of 3D Mapped Meshing
In the last post, some examples of 2D mapped meshing are given. Here we are going to look at some examples of 3D mapped meshing. Similar to 2D mapped meshing, the strategy is straightforward: divide the domain in such a way that all the subdomains meet certain requirements, specify the element size or the number … Continue reading Examples of 3D Mapped Meshing
The application of contact elements: A bolted beam-column connection
In this post, we are going to explore the application of CONTA174 (i.e. 3D 8-node face-face contact element). CONTA174 is used to represent contact and sliding between 3D target surfaces and a deformable surface defined by this element. It can be used for both pair-based contact and general contact. In the case of pair-based contact, … Continue reading The application of contact elements: A bolted beam-column connection
The application of MACRO and *DOWHILE
In this post, I will show an example of using MACRO and *DOWHILE. The APDL is developed to model an experiment as shown below. Essentially it is a clamped-clamped cracked beam carrying a body. An important feature of the body is that its mass distributes far away from its centroid, hence the rotary inertia would … Continue reading The application of MACRO and *DOWHILE
Examples of 2D Mapped Meshing
Some techniques in 2D mapped meshing
Large Lateral Deflection of Unequal Stiffness Springs
A two-spring system is subjected to a force F as shown below. l=10 cm, k1=8N/cm, and k2=1N/cm. F=5*2^0.5N. Determine the strain energy of the system and the displacements δx and δy. The solution to this problem is best obtained by adding mass and using the "slow dynamics" technique with approximately critical damping. Combination elements (COMBIN40) are … Continue reading Large Lateral Deflection of Unequal Stiffness Springs
3D Stationary Crack Analysis: J-integral and Stress Intensity Factor Calculation
We talked about 2D stationary crack analysis using KSCON in the last post. This time let's have a look at the 3D model using solid elements. A long plate with a centre crack is subjected to an end tensile stress. The sketch of the problem is as follows. A one-quarter model is used because of symmetry. … Continue reading 3D Stationary Crack Analysis: J-integral and Stress Intensity Factor Calculation
2D Stationary Crack Analysis: J-integral and Stress Intensity Factor Calculation
We talked about calculating J-integral and K1 using XFEM in the last post. XFEM is a powerful method as it eliminates the need to remesh crack-tip regions. However, there are some limitations. For example, material behaviour is assumed to be linearly elastic. The available fracture criteria are valid only for cracks in homogeneous linear elastic … Continue reading 2D Stationary Crack Analysis: J-integral and Stress Intensity Factor Calculation
XFEM-Based Stationary Crack Analysis
This post presents an example of stationary crack analysis based on the extended FEM (XFEM). A common way to model the stress concentration at a crack tip is using KSCON command which specifies a keypoint about which an area mesh will be skewed. For stationary crack analysis, reasonable accuracy can be achieved using KSCON, although … Continue reading XFEM-Based Stationary Crack Analysis