Ensayos Destructivos.

Destructive Testing Overview

Introduction to Destructive Testing

• Destructive testing is defined as a method that permanently alters the physical, chemical, mechanical, or dimensional properties of materials.

• This type of testing results in material destruction and can be categorized into four main forms: physical, chemical, mechanical, and dimensional.

Types of Destructive Tests

• The six primary types of destructive tests include:

• Tension (traction)

• Compression

• Shear (cizalladura)

• Torsion

• Bending (flexión)

Tensile Testing Process

Understanding Tensile Testing

• Tensile testing involves applying opposing forces to a small specimen to create tension until deformation occurs.

• The process requires generating stretching forces on the specimen to observe how it deforms under stress.

Laboratory Procedure for Tensile Test

• In the lab setup, a specimen with specific dimensions is placed in an extensometer for measurement.

• The extensometer measures stress and deformation during the test; data is collected on force and elongation.

Results Interpretation

• A graph plots stress against deformation showing elastic behavior followed by plastic deformation until failure occurs.

• The maximum tensile strength is reached before the specimen ultimately breaks.

Compression Testing Process

Overview of Compression Testing

• Compression testing is essentially the opposite of tensile testing; it applies compressive forces to deform the specimen differently.

Laboratory Setup for Compression Test

• Initial measurements are taken for length and diameter using calipers before applying compressive forces with an extensometer.

Observations During Compression Test

• As force increases, the length decreases while diameter increases until reaching maximum capacity where operations cease.

Shear Testing Process

Introduction to Shear Testing

• Shear testing involves creating a cut in the material through applied lateral forces.

Examples of Shear Tests

• Common examples include two blocks being pushed against each other or one block being sheared from both sides.

Understanding Material Behavior Under Stress

Identifying Forces and Deformations

• The discussion begins with identifying the forces acting on a material, indicating an approximate force of 15,000 units. This sets the stage for understanding how materials respond to different types of stress.

Torsion Testing

• An example of torsion is introduced, highlighting how twisting forces can lead to material failure. The speaker notes that this is commonly experienced when opening a soda can.

• Torsion results in helical deformation, where two opposing forces create torque that twists the material. This concept is crucial for understanding how materials behave under rotational stress.

• A demonstration of torsion testing shows gradual deformation as torque is applied, illustrating the transition from elastic to plastic deformation until failure occurs.

Flexural Testing

• Transitioning to flexural testing, the speaker explains how bending forces affect materials like beams or notebooks. This type of test assesses a material's ability to withstand bending without breaking.

• The flexural test setup involves applying force at specific points on a beam to measure its response until it fails. Observations include how cracks develop over time rather than instantaneously.

Resilience and Impact Testing

• Resilience in materials refers to their ability to absorb energy during impacts. This term parallels psychological resilience but focuses on physical properties in engineering contexts.

• The concept of tenacity is introduced as a measure of a material's capacity to absorb energy from impacts, which is critical for assessing durability and performance under sudden loads.

Charpy Impact Test

• The Charpy impact test measures resilience through controlled impacts on specimens. It quantifies energy absorption capabilities using pendulum mechanics.

• In this test setup, the specimen's position and calibration are essential for accurate measurements of energy loss during impact events.