الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
This research study is an application of reverse engineering to produce a centrifugal pump impeller as a marine spare part from glass reinforced polyester resin.
In this research the work frame structure will depend on the reverse engineering processes. The reverse engineering project divided into four stages, these stages are:
Stage 1: evaluation and verification Stage 2: technical data generation Stage 3: design verification
Stage 4: project implementation
The first stage determines which information is essential to continue the process and may be needed in the other stages data like dimensions, forces, stress and application req~irements.
In second stage the missing or inadequate technical data will be generated as drawings or preliminary calculations.
The technical data generated in the second stage should be verified by testing on one or many levels in the third stage.
In forth stage after tests and inspections are meeting the requirements needed to verify the design, there are many other steps needed to achieve• the final results (product).
According to the previous stages and applying it to these research studies it is clear that the first stage is gathering the data and finding out the documents and information available.
The second stage is studying the problems affecting the impellers and the type of the material used in producing it. Further not to forget the missing data generation likes calculating the stress and force distribution on the blade to find out which composite can achieve the requirements.
In sire” and foree deteonina’;on we will u., theoretical ways of deteonining the Stre” and fo”es applied to the blade impeile, (calcula’;ons and FEA softW”,e).
In the thkd stage the te”, aud inspec’;ons take place. The., IeSts are divided into two main tests erosion mte and abSO’P’;on mte. These tests lead to different types of results. The erosion test needs a design of leSt dg to make the teSt easy and acclmtte and it needs a jig to fix the sample against the water jet during the test.
The lest of e’”lon mle is using sea wate, as a testing media. The sea wate, is nnt pure wale, hecan., of containing a lot of Imp”’’’ies and sediments so the testing media is cailed siuny. This sluny erosion test dg is built fm labo”’tory use. This a_atus gives good control OVe, many of the teSt P8n1metet> such as jet pre”ure, jet velocity and Impact angle. The nozzle which is attached to the discharge line of the test dg pump is designed to reduce the pump discha”e line Cro” sec’;onal area to one third to increase the wale, velocity and Ware, jn”essure to apply a severe condition on the specimen.
The tests ,ig in which samples ”’e attached to a jig. This jig is to peonit a fixed impact angle of jet wate, and a concenttale amOunt ofwat”, at a specific area.
The teSt ’ig is ensudng that damage m erosion will ”” in the sU’face of the sample and not elsewh”’e in the sample, and the ability of ease change of the samples.
The erosion •.• te teSt is conceroed with the cha”,cteoiza’;on of wale, jet with sand and sediments (slony) erosion behaviou, of fou, different types of po lyme, ma”ix composites (PMC). The maiu aim of the present study is to examine rela,;onship between the ability of the samples to withstand the s”e”es and fluctua’;ng forees in one side and erosion rate in the other side.
The matedals tested in the p’esent Study are fou, different types of polyme, ma”ix composile namely =bon with cotton fibe,-, in phenolic ’esin, chopped glass fibe, 3mm with glass conlent 40% in polyeste, resin, chopped glass fibe, 5mm with glass content 60% in POlyeste’resin, chopped glass fibe, 3mm with glass Content 40% and 30 % CaC03 (calsume carbonate) filler in polyester resin.
Afte, p,epadng the teSt ,ig, the jig and the tested samples the erosion test should take place. The test will be eStablished in a continuous opem’;on at room tempemture fm 12 hours.The samples will be scaled before and after the test The weight loss divided by the total weight of the sample is named the erosion rate. During the erosion test a sample weight increase is appearing which leads us to the absorption rate test.
The absorption rate test is to immerse the sample prepared specially for this test in distilled water for 24 hours. The absorption rate is a gain of weight by the sample. The dimension of the sample which is used in this test is (50x25x3) mm.
The forth stage in the reverse engineering process is the finalization stage. This stage is the stage at which the final product should be appearing. The tests results collected in tables and plotted in curves and charts to figure out the suitable composite can replace the original specimen.
The final results of the tests are divided into erosion, erosion rate, erosion efficiency, absorption rate and cost comparison.
According to the weight loss and erosion rate the polyester resin 3mm glass fiber is the most suitable composite.
According the absorption rate the polyester resin 3mm glass fiber with CaC03 filler is the minimum absorption rate among the four samples because the good surface finish of the specimen which p~event the water absorption.
The result of the erosion efficiency comparison is used to show which sample is brittle and which is ductile.
Regarding the cost analysis, the polyester resin samples are less in cost compared with the phenolic resin price.
After collecting the results of the tests it is clear that the unsaturated polyester resin 3mm chopped glass fiber is the suitable and optimum specimen to replace the phenolic resin carbon fiber.
The last stage in the reverse engineering processes is finalization, a production of the final product which is the centrifugal pump impeller. The manufacturing procedure is adding the orthophtalic and the MEKP with 2% by volume to the resin and cobalt octuate is used as a promoter with 0.1 %. The resin mix was poured to the mould and vibrated to get rid of the air inside the resin. The gel time was about 40 minutes. The mould was made of a special type of silicon-rubber with excellent shape memory.