LTM Electrodynamic Testing Machine

Electrodynamic testing machines are used to determine material and component fatigue-strength in the fatigue life and fatigue limit ranges.

The LTM’s wide speed range allows it to be used for both dynamic fatigue tests and quasi-static tests. The oil-free drive, combined with ease of installation, makes the electrodynamic testing machine ideal for use in biomedical engineering and electronics, as well as for research and training. Typical examples include tests on hip-joint and knee replacements and dental implants. Other applications are tests on standard plastics and composites specimens, as well as aluminum and plastics CT and SEB specimens. The electrodynamic testing machine is available with loads of 1, 2, 3, 5 and 10 kN.

The Electromagnetic Drive 

The LTM linear motor testing machine is based on a patented electrodynamic drive system from ZwickRoell.

The drive was specifically designed for the relevant speed range

  • High positioning accuracy
  • Optimal control quality
  • High frequency rate 
  • Reliable test results

Key Advantages and Features

Description

The LTM is an electrodynamic testing machine with a drive based on linear motor technology. ZwickRoell's newly developed patented drive concept enables the LTM to be used for both dynamic and static materials and components testing. The low moved mass of the drive provides ideal conditions for performing fatigue tests with tensile, compression, and flexural loading.

The LTM is used in industries where oil-free and low-noise drive technology are preferred, for example, in the medical industry for standard-compliant testing of hip joint, knee, or dental implants.

Other typical application examples include fatigue and durability tests on standard specimens made of plastics, fiber composites and metals.

For components testing, the LTM is equipped with a T-slotted plate that can be adapted to components, and test fixtures quickly and easily as standard.

Intuitive operation via testXpert R and testXpert III software makes the LTM a genuine all-rounder for industrial purposes as well as for research and teaching at university level.

Advantages

  • High dynamic performance due to low moving mass
  • Wide speed-range enables dynamic as well as quasi-static tests
  • Low operating and maintenance costs with oil-free drive technology without additional supply feeds
  • Motor-driven traverse adjustment for convenient operation
  • safe setup mode as per EN 60204-1 via speed reduction to 10 mm/s
  • Simple manual crosshead locking via hand lever with electrical monitoring and LED status indicator
  • Long piston-stroke (60 mm) enables wide variety of applications
  • Operator-friendly testXpert R testing software with preset controller settings and availability of free controller definition for dynamic testing requirements
  • Intelligent testing software testXpert III featuring intuitive operation for static testing requirements.
  • Flexible use of specimen grips and fixtures over the entire dynamic product range
  • The electromagnetic drive was designed specifically for the speed range relevant to testing technology and features exceptionally quiet operation, optimum control quality and extremely high positioning accuracy
  • The travel measuring system is coaxial to the test axis and mounted near the specimen in the piston rod, enabling high positioning repeatability and precise piston travel measurement

Testing frequencies, which equal up to 100 Hz, depending on the test, ensure short test times, yielding high specimen throughput.

The linear motor does not require additional supply feeds, such as pneumatic, coolant, or oil. This reduces service and installation costs.

Operation is via testXpert® R for dynamic tests and testXpert® II for static tests. This software is intuitive and customized to meet testing requirements.

Wear-free components ensure maintenance-free operation.

The Displacement Measuring System

During the design stage, particular attention was paid to the positioning of the displacement measuring system—close to the specimen and in the center of the test axis.

The displacement measurement is coaxial and mounted near the specimen in the piston rod.

  • By avoiding displacement measurement errors, exceptional positioning and repetition accuracy can be achieved.

Technical Overview

LTM 1 / 1 HR

LTM 2 / 2 HR

LTM 3 / 3 HR

LTM 5 / LTM 10 

Type

LTM 5           Standard

LTM 5           + 250 mm[1]

LTM 10           Standard

LTM 10           + 250 mm[2]

Item No.

1008107

3001848

1008108

3001847

Fmax, dynamic

±5

±5

± 10

± 10

kN

Fmax, static continuous

±3.5

±3.5

± 7

± 7

kN

Piston stroke

60

60

60

60

mm

Positioning and repeat accuracy

±2

±2

±2

±2

μm

Speed range

1

1

1

1

mm/min

 

1.5

1.5

1.0

1.0

m/s

Maximum frequency[3]

100

100

100

100

Hz

Noise level at 1 meter distance, max.[4]

< 68

< 68

< 68

< 68

dB(A)

Load frame

Overall height of testing machine, max. (A)[5]

2510

2760

2715

2965

mm

Overall height of test frame, max. (B)

1980

2230

1980

2230

mm

Overall width

860

860

860

860

mm

Overall depth

850

850

850

mm

Height of mounting table (C)

720

720

720

720

mm

Column diameter

65

65

65

65

mm

Test-area height, max. (D)[5]

1106

1356

1106

1356

mm

Frame stiffness at 1000mm crosshead separation

300

300

300

300

kN/mm

Total weight[6]

941

966

1040

1065

kg

Working area

Working-area width

460

460

460

460

mm

Working area width without load cell, max. (E)[5] [7]

920

1170

920

1170

mm

Working area height with load cell, max. (F)[5] [7]

781

1031

781

1031

mm

Top crosshead adjustment

Motorized

Top crosshead clamping

Manual

Crosshead clamping electrically monitored

Yes, with signal indicator

  1. Extended load frame (required for use with a temperature chamber)
  1. Extended load frame - required when using a temperature chamber
  1. Depending on load ratio (r-ratio) and test amplitude
  1. Depending on output required, environment, testing arrangement, testing type, frequency and specimen type. Measured at 1m distance, free field, analog to DIN EN ISO 11205
  1. Highest crosshead position
  1. Testing machine only, without electrical cabinet, accessories and options
  1. Median piston position

LTM 5/10 design

LTM 1/2/3 design

testControl II control electronics

testControl II measurement and control electronics

Control frequency

10 kHz

Measured value acquisition

10 kHz, 24 bits, arithmetical

Slots

5 x module bus

PC interface

GigaBit Ethernet

Integrated safety concept

- 2-channel specification for maximum safety

 

- interface for interlocked safety doors

 

- Emergency Stop link interface

Display-equipped remote control unit

set-up or testing mode

 

- Emergency Stop button

 

key-switch for switching between setup and testing modes

Dimensions

Height

750

mm

Width

600

mm

Depth

600

mm

Weight approx.

102

kg

Length of cable between LTM & testControl II

500

mm

Protection class

IP 54

Safe Medical Products Thanks to Innovative Testing Technology

Fatigue tests are a fundamental component in the development of safe and durable implants. Extensive testing is especially necessary during the transfer of prototypes to the validation process. Komet Medical, the surgical division of Gebr. Brasseler based in Lemgo, Germany, uses a ZwickRoell testing machine with linear drive for these tests.  
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