# Homework, Quizzes, Simulation Examples — Contact — Lesson 5

### Simulation Examples

Several simulation examples are provided here. Each of them comes with a description file, video instruction, and Ansys simulation file. All of the simulations are conducted using Ansys simulation software. Download the student version of Ansys here.

#### (1) Bowling Ball Impact Simulation

This simulation uses a bowling ball to illustrate the idea of contact. Frictionless body interaction is defined between the ball and the pins and within the pins. Conduct a simulation without contact and check the results. the zip file and extract the contents. Go through the Readme file. Follow along with the provided How To Video file.

#### (2) Effect of Friction — Simulation of a Log Pile

This example aims at demonstrating the effect of friction. The movement of a wood log pile under gravity load is modeled. A simulation with frictionless contact between logs is conducted,
then repeated by changing the contact to frictional, adding friction high enough help the pile hold itself together. The simulations model the logs as rigid bodies because their strains are not of interest in this simulation. Download the zip file and extract the contents. Go through the Readme file. Follow along with the provided How To Video file.

#### (3) Press Fit Pin in a Plate

In this simulation, a pin is modeled in a plate. There is a geometric interference between the pin and the plate hole. This interference between the pin and the hole is resolved using proper use of contact and a sub-step to simulate the press fit. Download the zip file and extract the contents. Go through the Readme file. Follow along with the provided How To Video file.

### Homework

#### (1) Comparison Between Bonded, Frictionless and Frictional Contacts

A bolt joint is a common joint type in structures. It connects two bodies and carries both tensile and shear loads. This simulation compares different contact types in a bolted joint and emphasizes the importance of choosing a realistic contact type. Redo the simulation, compare the results and answer the following questions.

(a) Which type of contact type provides the highest stiffness of the joint? Bonded, frictional or frictionless?

(b) What role does the bolt pretension play here? Without the bolt pretension, will the difference between frictional and frictionless contact become larger or smaller?

#### (2) Pushing a Block Up an Incline

This model simulates pulling a block up an incline with friction between the block and the ground. Follow the instructions and redo the simulation. Answer the questions below.

(a) In the first step, what is the frictional force magnitude and direction? Do the hand calculation first and compare it with the simulation result.

(b) If you change the contact type to frictionless, what is the resulting pulling force? Do the hand calculation first and compare it with the simulation result.