eXpert 2600 Dual Column Testing Machine

Introduction

Manufacturers of metals, including  producers of raw material or finished metal products, need to pass compliance standards before shipping their product. Tensile testing is imperative for ensuring a safe, high quality material and avoiding the major liabilities associated with providing non-compliant products. These actions will keep the end consumer satisfied and dramatically reduce the chance of failure in the field. Below, we will discuss ASTM E8, an international standard for determining the tensile strength of metals.

ASTM E8: Specification for Measuring Tensile Strength of Metals

The ASTM E8 test provides data on the strength and ductility of metals under uniaxial tensile forces. The tensile strength of a metal is essentially its ability to withstand tensile loads without failure. Ductility, on the other hand, measures a material’s ability to deform under tensile stresses.  This is an important factor in metal forming processes since brittle metals are more likely to rupture. Metals that break or crack when stressed cannot be transformed during hammering, rolling, or drawing.

Technicians who conduct tensile testing of metals measure a number of mechanical properties to determine the material’s quality. The figure below is a stress-strain curve which provides a graphical representation of these mechanical properties. Some of the critical measurements include: peak stress or ultimate tensile strength (Point D), rupture or fracture point (Z), offset yield strength (B), and percent elongation at break.

Why is Tensile Testing so Important?

Metal fabricators are challenged to provide materials to the automotive, aerospace, and construction sectors that have the right  strength and ductility.  These sectors  follow stringent safety regulations.  The performance of their materials are a matter of life or death – cars and airplanes cannot fail, and buildings must stay standing. For instance, according to AP news reports, the recent disaster in a factory in Bangladesh – more than 1100 workers perished when the building collapsed — was in part caused by loading the building beyond its designed structural capacity.  Properly designed and tested structural additions may have averted the catastrophe.

A subset of the metal industry worthy of special mention is the research and development of novel metal alloys.  Metal alloys are designed to provide material properties tailored to specific applications and uses. Load bearing steel beams are fabricated with high strength materials, but steel that is used for framing in walls needs to have a certain amount of ductility to allow it to be formed into shape and to enable fasteners, such as drywall screws, to work — if the steel is too brittle, it will crack. Tensile testing is the most common method for determining these material properties. Alloys are tested for strength and ductility at all phases of the product life-cycle, from R&D to inspection of incoming materials to quality checks on finished goods.

Another good example of tailored material properties for specific applications is the automobile, in which the design of the frame in the engine compartment utilizes different materials than the doors and pillars that hold the drivers and passengers. The right combination of ductility and strength in the right places improves safety and crash management through Energy absorption.

The automotive and aerospace fields also invest heavily in research and production using lightweight materials, which reduce the overall fuel required to move a machine, but must still meet the strength requirements of the application.  Having fast, accurate feedback on the strength of the metals used is critical to all of these applications — how can ADMET help?

ADMET Solutions for Tensile Testing

For meeting the challenges of tensile testing, ADMET provides the eXpert 2600 Series Dual Column Universal Testing Machines equipped with wedge grips, extensometers, and the PC-based MTESTQuattro(R) Materials Testing Software and Controller.  eXpert 2600 Series Testing Systems are offered in capacities from 5kN to 250kN and are well suited for determining the tensile properties of metals.

Materials testing systems are a must for determining the strength and ductility of metal and metal alloys. To learn more about ADMET’s eXpert 2600 Series Universal Testing Systems or other metal testing solutions, please contact us!

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Challenge

With iconic design, pioneering innovation, and a precedent of leadership, the Sun Path Products line of harness container systems continues to envision what other rigs might someday be, and value from today forward. Sun Path Products is dedicated to offering the finest parachuting equipment for both the sport and military markets. Continuous research, development, and testing coupled with equipment evaluation by some of the most exceptional skydivers in the world position Sun Path Products to be one of the foremost skydiving equipment manufacturers in the global market.

Clearly these products need to work. Failure is not an option. Specifically the material testing challenge had to meet Federal standards, FED-TM-STD – 191A – Section 4108. Sun Path Products existing materials testing system from a market leader had reached the end of its 30 year life. The challenge was to find an economical replacement which was totally reliable, easy to use, deployed today’s technology and could generate key metrics automatically.

Solution

The company acquired the eXpert 2613 Universal Testing System with an eP2 Digital Controller with GaugeSafe software from ADMET.  The objective being to track, analyze, and report the data measured during the test and to assess the strength of their webbings and hardware. Dave Singer, Director of Engineering at Sun Path Products, explained that his company chose an ADMET solution because it was very cost-effective relative to the reliability, ease of use and quality of engineering demanded by the ultimate end use of the product.

eXpert 2654 with 100BT Webbing Grips

Results

The customer’s success criteria were met:

1. Execute key tests to Federal Standards: Tensile test to break, cycle test (load & unload multiple times).
2. Perform the tests on specific materials, namely webbing and associated hardware.
3. Produce analysis results: Load vs. position chart, maximum load at failure, elongation.
4. Deliver printable / exportable test reports with ability to auto save test results.
5. Deliver the maximum force required: 10,000 lbf.

eXpert 2600 with extensometer

Whether a company manufactures textiles, plastics, elastomers or stronger materials, it is necessary that all products undergo sufficient quality control procedures. Along with ensuring materials are superior, all regulations such as ASTM specifications need to be followed before bringing items to market.

One dual-column universal testing machine that is capable of performing peel, tension, compression and flexure tests is the ADMET eXpert 2600 series. Along with a large variety of tests this machine can conduct, a variety of businesses reach out to ADMET for the eXpert 2600 series due to the many types of materials it can accomodate.

This universal testing machine is able to hold and measure the properties of a variety of materials including plastics, metals, composites, adhesives, strapping, textiles, webbing, rope, wood and foam.

One reason that customers come to ADMET to purchase the eXpert 2600 series is because of its ability to provide more force and a higher distance of travel compared to ADMET’s other products. Because of its dual-column capabilities, this machine is able to handle stronger materials than the single-column systems, as it reaches past a 2,000 lbs breaking force. This series also includes superior axial alignment, stiffness and crosshead guidance.

Another benefit of this series is that these dual-column machines can incorporate environmental chambers, thereby allowing testing of objects and specialized materials in both hot and cold climates.

This system is offered in both tabletop and freestanding format. Benchtop models can test adhesives, biomaterials, metals, films, packaging, plastics, textiles, wires and other materials at forces between 2kN and 50kN. Freestanding models, on the other hand, are able to exert a force up to 200 kN.

The engineering and customer support teams at ADMET provide a customizable, reliable and trusted product that exceeds all ASTM/ISO accuracy standards.

Each testing machine ADMET offers comes with one of two servo controllers – either the MTESTQuattro PC-Based controller or the standalone eP2 Digital Controller. The MTESTQuattro offers extensive options in control, data attainment, analysis and reporting while the eP2 Digital Controller offers a more simplified interface for more basic tests.

Other accessories must be purchased along with eXpert 2600 series, such as grips, fixtures and cutting tools. Optional items – environmental chambers, extensometers or temperature-controlled baths – may also be added to increase the versatility of the machine. In addition, extensometers and deflectometers provide higher accuracy for materials testing.

After procuring the testing system and all necessary items, ADMET provides training and support to our customers. Along with manuals, tutorials and introductory online educational resources, our staff can deliver on-site training. Free phone and email support is also provided throughout the life of a system.

So why would a business owner choose to purchase the eXpert 2600 series from ADMET? The answer to this question includes ADMET’s ease of use, specialized configuration to suit consumer needs, customer-centric products and services, best value for product type and highly accurate systems.

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Check out our latest page on ASTM D1708 here

Grips and extensometer for ASTM D1708 microtensile testing

Summary:

Historically, test method ASTM D1708 has been used to measure the tensile and elongation properties of plastics that have little amount of material available.  There are also many other ASTM test methods for specific materials (FEP, ETFE, PTFE) that reference the same test method a list of which is referenced below.  A change has been made to the ASTM D1708 tensile specimen shape so that it now is the same as the shape found in ISO 12086-2.  ASTM D1708 is no longer the preferred plastic microtensile method as ASTM recommends the much more common ASTM D638 tensile test using the very small type V specimen shape.  If interested, another ADMET page discusses ASTM D638 here.

The convenient feature of D1708 is that the specimen shape is such that an extensometer is not required to perform the test.  Rather, the universal testing machine’s built in jaw separation position is sufficient to measure elongation.  It becomes critical however that you have a very accurate initial jaw separation which happens to be less than an inch.

Equipment Required:

1. Universal Testing Machine (UTM) of the constant-rate-of-crosshead-movement variety.  I’m not aware of any manufacturer that makes anything but this type anymore.  However, the UTM should be servo-controlled to maintain the set speed throughout the test.
2. Load Cell accurate to at least 1% of the reading.  Also, the breaking strength of the material should be between 1/100th and the full capacity of the load cell.  For example, a 100 lbf load cell should be used to measure from 1 – 100 lbf.
3. Tensile Grips of the “vise” or “side action” variety so as not to interfere with the elongation measurement.  Serrated, plain, and rubber coated jaw faces can be used.  Pneumatic grips of the “side action” type can also be used.  Self-tightening grips such as eccentric roller and wedge styles are not good for this test.  Eccentric roller grips are hard to set the jaw separation properly and wedge grips have the same problem but can also add an undesirable compressive load on the sample.  Systems that adjust grip separation automatically to accommodate a compressive load then adjust the gauge length.  It’s not tricky as it sounds if you use a simple pair of manual tensile vise grips.

The cost for a system that meets the accuracy requirements of the specification and include all the items above generally start at around $ 8,000 USD.  Depending on vendor and options chosen, typical 1kN – 50 kN systems range in price from $8,000 – $ 40,000 USD.  The major cost driver with these systems is the maximum force capacity of the system.  1 kN & 5 kN single column systems are sufficient for many materials when testing to a microtensile method and are the most cost effective.  Larger capacity 10, 25, 50, 100 kN and higher dual column systems are also available that can perform this test as well and performing other high capacity tests.

Other Microtensile Test Methods:

1. ASTM D2166 Section 11.4 – Tensile Properties of FEP Fluorocarbon Molding and Extrusion Materials
2. ASTM D3159 Section 11.4 – Tensile Properties of Modified ETFE-Fluoropolymer Molding and Extrusion Materials
3. ASTM D4745 Section 12.4 – Tensile Properies of Filled Compounds of Polytetrafluoroethylene (PTFE) Molding and Extrusion Materials
4. ASTM D4894 Section 10.7 – Tensile Properties of Polytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion Materials
5. ASTM D4895 Section 10.7 – Tensile Properties of Polytetrafluoroethylene (PTFE) Resin Produced From Dispersion

Video of a Micro tensile test:

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ADMET’s is introducing a new member to its popular eXpert 2600 series dual column testing systems. Over our 21 years in business, we’ve realized that fitting a 6 foot tall universal testing machine in some office or lab spaces can be a challenge.  In addition, most biomedical, metal, ceramic, adhesive, and hard plastic testing applications do not require 48 inches of vertical crosshead travel. The ADMET eXpert 2600ST solves these problems by featuring shorter columns that allow it to fit almost anywhere.

Crosshead travel on the 2600ST is limited to 24″, reducing overall system dimensions to 44″T x 34″W x 20″D. The eXpert 2600ST is available in capacities up to 50kN and speeds up to 100 in/min. In addition, if your testing requires both linear and torsion, systems can be equipped with torsion actuators up to 20NM.

Compression, shear testing, and bend tests are easily performed with the eXpert 2600ST. Those interested in tensile testing should consider material length and elongation. If 24 inches of travel satisfies your requirements, tensile testing will be a breeze.

For 21 years, ADMET has produced universal testing machines, controllers, software, grips, and fixtures. In addition, we customize our systems to meet custom requirements. We welcome the opportunity to find a solution for you. Please contact us at 1-800-667-3220 or info@ADMET.com.