Because each test standard has a different test material, before we choose a vibration test system, we must first decide which test standard we need to pass.
1. Selection of vibration systems for ISTA 1A
We can see that the vibration test for the ISTA 1A test standard is as follows if our test standard is ISTA 1A.
Our simulated transportation test machine can match the test requirements for ISTA 1A or ASTM D999’s fixed displacement vibration test; we simply need to select the right model based on the size and weight of our largest sample.
(Another Related Article: Interpretation of the ISTA Test Standard)
2. Selection of vibration systems for ISTA 3A
If our test standard is ISTA 3A, we can see that the vibration test for the ISTA 3A test standard is as follows
We may infer from these test results that the displacement of this test condition is big(58.72mm peak to peak) and that it is a random vibration test; hence, the equipment we supply must have a displacement of more than 3 inches to comply with the standard.
(Another Related Article: Vibration Test 101: A Full Guide)
2. Case Analysis
We must study individual scenarios because this test standard includes different test regulations for each package. Here is an inquiry from a Korean customer
Our customer from a laboratory would like to set up a new ISTA 3A Lab. Below is the customer product information. Would you mind proposing an Electrodynamic Vibration Test system? Thanks.
Package size: 300mm x 300mm x 150mm
Packageweight:20kg
There is no requirement for a horizontal slip table because the customer’s sample is packaged in standard cartons and may complete the triaxial test by switching the direction of the packaging. Since the vertical test table we give is 400x400mm>300x300x150mm and weighs 15kg, it must be larger in size than the customer’s sample in order to accommodate the sample.
We will now determine the capacity needed for our test and select the proper equipment. The reference selection formula is as follows:
Selection formula
Force=Moving mass X maximum acceleration X safety factor
Moving mass= sample weight 20+ armature mass 10+ table weight15=45kg
F=MA*1.3=45*0.53g*1.3=31kg. f
Because the maximum displacement required by this test standard is 58.72mm, the displacement of the vibration system we provide must be more than 58.72mm in order for it to meet the ISTA 3A standard, as can be seen from the calculation result. The smallest equipment needed for this displacement is a 10kN vibration system, so the vibration system we offer has a vertical table size of 400×400 and a 10kN vibration system with a displacement of 76mm.
(Another Related Article: Environmental Test 101: A Full Guide)
3. Selection of vibration systems for ISTA 6 Amazon
Here is an inquiry content:
I’m interested in your random vibration test equipment. Do you know if this machine’s specs fit the Ista 6 Amazon machine criteria? Also, how much would this machine cost in US dollars?
Test standard ISTA 6 Amazon needs a big displacement of 47.12mm (1.855 in peak to peak)but a relatively tiny acceleration of 0.53g, similar to ISTA 3A. The largest test sample size must be known in order to choose the appropriate testing table because the displacement of the equipment must be greater than 3 inches, and the smallest vibration testing machine that satisfies this displacement is a 10kN shaker.
The following information was also given by the customer.
- The box is 650x650mm in size and weighs 50kg
- The head expander 800x800mm (vertical table) was chosen with the customer’s sample size in mind and weighing 46 kg, while the customer’s sample weighs 50 kg.
The suitability of a Specific Test System can be evaluated in terms of the following:
- Force Requirement (kg. f)
- Moving MASS x G = F x 1.30= Desired Force Shaker System
- Determining Moving MASS: Test Articles, Slip Tables, Head Expanders, Fixtures, and armature
- 10kN shaker: 1000kg.f (random force)/1.3/1.05=732kg>sample weight50kg+ armature mass 10kg+ table weight 46kg
The project’s solution is a 10kN(VS1000-3) shaker with an 800×800 head expander and a two-channel controller (The vibration mode of this test standard is random vibration with no other functional requirements)
4. All random vibration testing requirements of the ISTA standard
The ISTA standard specifies the following maximum acceleration and displacement criteria for random vibration.
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