OPERATING PRINCIPLES OF THE UNIVERSAL TESTING MACHINE

What is the primary equipment used in mechanical testing experiments?

The Universal Testing Machine (UTM).

What does the complete set of attachments for the UTM include?

• Grips (for tension testing)

• Compression plates

• Shear test fixtures

• Bending attachments

• Extensometer

• Brinell hardness setup

What is the Universal Testing Machine (UTM)?

A versatile apparatus designed to perform various mechanical tests by applying controlled forces.

What are the two major components of the UTM?

• Control Panel

• Loading Unit

What is the main role of the Loading Unit in the UTM?

It is responsible for applying force to the test specimen.

What is at the core of the loading unit?

The main hydraulic cylinder, which houses a piston that moves vertically to exert the load.

What parts provide structural support and guide vertical motion in the UTM?

The base and supporting columns.

What do the upper and lower crossheads do?

They hold attachments and transfer the applied load to the specimen.

Which crosshead is typically movable and how does it move?

The lower crosshead; it moves via hydraulic action or a screw mechanism.

What are grips or jaws, and what is their function?

They are specimen holders that secure the specimen in place.

How are grips adjusted to hold the specimen tightly?

Helically, using a handle.They can be adjusted or tightened using a handle or mechanism to ensure a secure fit.

What attachments can be installed depending on the test type?

• Bending plates

• Compression plates

• Shear fixtures

What is the first step before conducting any test on a UTM?

Select the appropriate load capacity range using the range selector knob (e.g., 10, 20, or 40 tons).

Why must the pendulum and control weights be adjusted?

To ensure accurate load readings.

What must be done if graphical results are needed?

• Insert ink into the pen holder

• Wrap recording paper around the drum

Which load range gives more accurate results for a 6-ton specimen: 10-ton or 20-ton?

The 10-ton range gives more accurate results.

What should be done to all settings before beginning a test?

All settings must be verified and adjusted according to the selected procedure.

What is the first step when performing a tension test?

Select the appropriate job and adjust both upper and lower grips.

What should be applied to the specimen's tapered surfaces or grooves?

Grease.

How is the specimen inserted into the groove?

Use the upper grip handle to insert it securely.

What do you do with the valves during initial setup?

• Close the left valve fully

• Open the right valve briefly to slightly lift the lower table

• Then close the right valve immediately

Why do you adjust the pointer to zero using the knob?

To eliminate the dead weight of the lower table.

How do you lock the specimen in position?

Use the job operating handle.

Which valve is opened to begin applying load?

The left control valve.

What does the dial pointer show when the specimen breaks?

• A slight return in the pointer

• The value at that return = breaking load

• The maximum value reached = ultimate load

What attachments are used in a compression test?

Compression plates (attached to the upper head and lower table).

Where is the specimen placed in a compression test?

Between the compression plates.

What must be done to the lower table before testing?

Raise the lower table to zero the dial gauge.

How is the load applied in a compression test?

Gradually, just like in the tension test, until the specimen fails.

Where is the bending table placed during a flexural test?

On the lower crosshead, aligned with the center of the lower table.

What must be adjusted before placing the specimen?

The support spacing and installing back stops or stoppers if needed.

How is the specimen positioned for a bending test?

Across the supports of the bending table.

What applies the load in a bending test?

The upper crosshead’s bending attachment.

How is the test conducted?

Similar to the tension test, applying load gradually and monitoring for failure.

Where is the specimen placed in a Brinell Hardness Test?

On the lower table, then raised until it contacts the indenter.

How is the zero-reference point adjusted?

Using the lower crosshead.

How is the load applied in the Brinell test?

Slowly, until the desired load is reached.

How is the load released after testing?

Gently, using the left control valve.

What is observed after the test?

A circular impression on the specimen (usually 5–10 mm in diameter).

What tool is used to measure the impression’s diameter?

A microscope.

What is calculated at the end of a Brinell Hardness Test?

The Brinell Hardness Number (BHN).

What fixture is mounted for a shear test?

A shear test fixture that includes a cutter.

Where is the specimen placed during a shear test?

Inside the shear fixture on the lower table.

What is done before applying load in a shear test?

Raise the table to zero the dial gauge.

How is the load applied in a shear test?

Gradually, until the specimen fails.

What does it mean if the specimen breaks into 2 pieces?

It’s a single (angle) shear failure.

What does it mean if the specimen breaks into 3 pieces?

It’s a double shear failure.

What is the purpose of an extensometer?

To measure elongation of a specimen under load over a specified gauge length.

With which machines is the extensometer used?

UTM or tensile testing machines.

What is the least count of an extensometer?

0.01 mm

What is the maximum elongation an extensometer can measure?

Up to 3 mm

Why is elongation measurement important?

To determine material properties like proof stress at a given percentage of elongation.

What type of machine is the WEW-1000D?

A Computer Display Hydraulic Universal Testing Machine.

What types of tests can the WEW-1000D perform?

• Tension

• Compression

• Bending

• Shear (for steels and metals)

• Also compression/bending tests for plastics, cement, concrete

How does the machine operate hydraulically?

Using a plunger-type high-pressure pump inside the ergometer, driven by a motor.

What is the relative error in the test readings of this machine?

Less than ± 1%.

What makes the machine user-friendly?

• Easy operation

• Accurate & reliable readings

• Comfortable height for operating & observing

What special display feature does the machine have?

it can display the loading speed and allows adjusting it based on specimen requirements.

What are the two main structural components of the WEW-1000D Hydraulic Universal Testing Machine?

• Main body

• Ergometer

How many supports are fixed on the base and what connects them to the upper beam?

Two supports fixed on the base with nuts, connected to the upper beam.

Where are the other two supports fixed?

One on the middle of the beam, the other on the operating platform.

What do the four supports together provide?

A space to fix the specimen for tension, compression and bending tests.

What happens when the oils pump lifts the piston?

The operating platform rises, whch then lifts the two supports and upper beam.

Where are the upper and middle jaws located?

• Upper jaw → on the upper beam

• Middle jaw → on the middle beam

How does the middle beam move?

By the running of screws on the two supports.

What do the up and down signs on the lift control button indicate?

They show the direction of movement for raising or lowering the middle beam.

What are the most important parts of the UTM’s main body?

The oil cylinder and piston.

What is special about the piston’s touching surface?

It is precision finshed with proper spacing and oil film to allow smooth, low-friction movement.

What causes the piston, beam and operating platform to rise?

Oil flowing into the oil cylinder.

What happens when the piston rises?

It lifts the beam and operating platform until load applied to the specimen.

Why must oil be kept pure in the UTM system?

To prevent impurities or iron dust from entering and damaging the cylinder-piston surface, which affects test accuracy.

What must be done before installation if there's dirt or soil on the cylinder or piston surface?

The touching surface must be cleaned to avoid test errors or damage.

What accessories come with the main body of the UTM?

Tensile and bending accessories.

What is essential aside from machine accuracy to get reliable test results?

The operator must know:

• Proper operation steps

• Testing methods for different materials

• Material properties

What are the first two steps in the operation process?

• Power On

• Pump On

What is the next step after powering the machine and pump?

Clamping the specimen properly.