CMT-Lesson 7

• Universal Testing Machine


  A type of mechanical testing equipment that is utilized for determining the mechanical properties of various materials, such as tensile strength, compressive strength, bending strength, and shear strength
• Universal Testing Machine (UTM)


  • Works by applying a controlled tensile or compressive load to the specimen being tested and measuring its response
  • The term "universal" signifies its versatility and capability to conduct a wide range of mechanical tests on various materials
• Main parts of UTM

  • Loading Unit
  • Control Unit
• Loading Unit


  • Where the ACTUAL LOADING of the specimen takes place
  • Includes: Load Frame, Upper Crosshead, Lower Crosshead, Elongation Scale
• Load Frame


  • Can be constructed using a SINGLE SUPPORT or TWO SUPPORTS
  • Includes: Upper Crosshead, Lower Crosshead, Table that the specimen is set on for the compressive strength test
• Upper Crosshead


  • Used to CLAMP ONE END Of the test specimen
• Lower Crosshead


  • MOVABLE crosshead that can be adjusted vertically along its axis, usually controlled by a controller button
  • Allows for accommodating specimens of different sizes and shapes, ensuring proper alignment and positioning within the UTM
• Elongation Scale


  • Measures the RELATIVE MOTION of the upper and bottom tables
• Control Unit


  • Provides the ADJUSTMENTS in load application and the associated test result
  • Includes: Hydraulic Power Unit, Load Measuring Unit, Control Devices
• Hydraulic Power Unit


  • Consists of an OIL PUMP that provides non-pulsating oil flow into the main cylinder of the load unit
• Load Measuring Unit


  • Has a PENDELUM DYNAMOMETER unit that has a small cylinder with a piston that moves with the non-pulsating oil flow
  • Its accuracy controls the overall accuracy of the machine
• Control Devices

  • Electric Control Devices - uses SWITCHES to move the crossheads and to turn on or off the unit
  • Hydraulic Control Devices - has a right CONTROL VALVE that applies a load on the specimen, and a left control valve that releases the load application
• Tensile Test


  1. Provides information about the tensile strength, yield strength and ductility of the metallic material

  2. Measures the force required to break a composite or plastic specimen and the extent to which the specimen stretches or elongates to that breaking point
• Compression Test


  1. Measures the maximum amount of compressive load a material can bear before fracturing

  2. The test piece, usually in the form of a cube, prism, or cylinder is compressed between the platens of a compression-testing machine by a gradually applied load
• Adhesion Test


  1. Measures HOW STRONG THE BOND between two materials is

  2. Can be done in terms of load, stress, energy, or work required to break the interphase
• Pull-out Test


  1. Typically performed to assess the ANCHORAGE or pull-out capacity of geosynthetics

  2. Important in situations such as retaining walls, slopes, and bridging over voids, where the geosynthetic is anchored into stable ground that is outside the zone of failure
• Bending Test


  1. Used to determine the STRENGTH and DUCTILITY of materials

  2. Involves bending a specimen until it fractures

  3. Results can be used to predict the behavior of the material under various conditions, such as tension or compression
• Tear/ Hysteresis Test


  1. Used to determine a FOAM'S ABILITY to retain its original firmness properties

  2. Unlike other durability tests, Hysteresis can be performed quickly on a variety of foam samples
• Functions of UTM (TCAPBT)

  • Tensile Test
  • Compression Test
  • Adhesion Test
  • Pull-out Test
  • Bending Test
  • Tear/Hysteresis Test