Hi, I do not know if this will be a complete answer but I will try. From a modeling point of view normally a punch test can be modeled easily using a 2D model, which is capable of give you all the information required stress distribution at the end of the test, deformation of the plate etc. COD and 4PB from my experience are used normally to evaluate crack initiation and propagation, at any temperature (depending by the application). Furthermore the plate thickness plays an important role in the choose of the test that you would like to perform. Here I attach you some documents, which can be helpful to solve your issue. I hope so.

Kindest regards

http://www.npl.co.uk/upload/pdf/Louise%20Crocker.pdf

http://www.maneyonline.com/doi/pdfplus/10.1179/1743284713Y.0000000278

http://www.citg.tudelft.nl/fileadmin/Faculteit/CiTG/Over_de_faculteit/Afdelingen/Afdeling_Bouw/-_Secties/Sectie_Weg_en_Railbouwkunde/-_Leerstoelen/Leerstoel_Wegbouwkunde/-_Publicaties/-_Publicaties_2009/doc/Theoretical_rilem.pdf

Hi Mr. Daniele,

Thank you very much for your answer ,

We can predict the plastic deformation or fracture mechanism of plate by doing tensile test or fracture test like charpy or COD ... etc . so we don't need impact of punching test on plate.

I thnk this related to the stress in those test will be in one direction and the stress in punching or impact on plate will gave stress in two direction and this can difficult to predict it accurately by modeling also many type of stress will occur in the same time during punching and impact like bending stress near support and another bending occur at center of plate for this reason the fracture mechanism will depend on many things like plate thickness, dimension , support type, material micro structure and exist of defect or not , and difficult to predict it by modeling .

Do you agree with me ? if not can you tell me what your opinion if yes can you add or correct some what I wrote.

I just to write proposal of my Ph.D research and try to find answer why i will doing impact and punching on plate  .

thank you ,

Best regards,

Plate impact tests generally are carried out at very high rates of loading.   Charpy and tensile tests are used to investigate much lower strain rate phenomena.  Different tests for different strain rate regimes.  

A Punch shear test on plate is often used to explore failure modes that are not occurring in either a charpy or tensile test. 

Hope this helps.

JMD

Dear Mr. Joseph,

Thank you a lot for answer.

But there is also drop weight or impact on notch specimen or small specimen , why in this case we need doing the impact or drop weight on plate ?

You are talking about two different things and I think that is the source of confusion. One is the plate punch test and another is the plate impact test. Let us see the plate punch test first. This will give you information about the deformation behaviour of the material under equi-biaxial state of stress (you can get a similar info from performing a bulge test). This information (bi-axial behaviour) is essential for material modellers since a tensile test performed under uniaxial condition is inadequate (sometime bi-axial tests are also performed using cruciform specimen-a + shape geometry). The information obtained is treated as the material behaviour derived under plane stress condition in material models. Some of the military applications require information on penetration resistance (and the local microstructural changes in the process) of materials. In those cases, plate penetration tests are carried out using fast moving projectiles (the one pointed out by Mr. Joseph). I do not think this falls under category of plate punch test you are talking about.

Now let us come to the second topic...plate impact test. In some applications (eg., ship building) you also want to know how far a crack will grow before it stops under a constant dynamic loading. This is called crack arrest toughness. There is an ASTM standard for performing this test (I do not remember the number right now, but can come back to you). This usually requires a large plate with a special notch geometry and the crack will be allowed to open (grow) using a wedge and a free falling mass. The data then will be used to get a crack arrest toughness (Kia). When you do a impact test or a regular fracture toughness test, how do you get a K value corresponding to crack arrest? Impact specimen is too small so there won't be enough volume of material to arrest the crack. Regular fracture toughness test is performed under a continuous increase in displacement and there is no way that the crack will stop growing, even if you choose to take large plate (assuming you have a huge test frame to handle this!!). You refer to some open source literature on crack arrest toughness.

Hope this clarifies your doubts.