Mathematical modeling of the eddy current testing of delamination cracks in multilayer CFRP objects

We propose an approximate mathematical model making it possible to obtain estimates of the change in the eddy current signal under the influence of delamination in multilayer carbon fiber reinforced plastic (CFRP) objects. We give the dependences of the change in the eddy current signal on delamination in the CFRP objects for a new flaw detection method based on the comparison of eddy current signals from CFRP layers grouped by angular orientation.

P1552CAN WE GET ADEQUATE DIALYSIS WITH LIQUID AT 300 ML/MIN ?

Background and Aims The portable HD monitors achieve a good adaptation with HD dialysate at 200ml / min using the concept of saturation of the HD dialysate. We decrease from 800ml / min to 500ml / min with good adaptation some years ago. To assess the effectiveness of HD in both HD-standard and HDF-online with dialysate flow at 300ml / min by establishing approximate mathematical model of clearance. Methods We conducted an HD session with dialysate flow at a speed of 300ml / min, half week session to 52 patients in our unit. We value vascular access, session time, liters of blood-purified and total infusion in HDF online. We review HD monitor and dialyzer. We perform pre and postHD blood determinations: Urea, B2microglobulin, P and uric acid, assessing urea reduction rate (PRU), b2microglobulin reduction rate (PR2microg) with both dialysate flows at 300ml / min and 500ml / min. We also have evaluated the differences between the two methods. In the HD dialysate flow we determine at 300ml / min at 5, 10, 30, 45 and 60min (total dialysate collection in the first hour with sample of the mixture) urea, B2microg, Uric acid and P and at 2, 3 and 4 hours establishing a mathematical model with an approximation curve in both HD and online HDF. Results Five patients in standard HD (4h), 35 HDF online (4h) (x Liters infused 24.87 ± 2.79 l) and 12 short-daily HD (2h30min). 18 catheter and 34 FAV. Xliters purified blood = HD daily 54.41 ± 5.63l, HD standard 87.38 ± 6.01 and HDFonline 82.02 ± 16.13l. The xPRU = 76.17 ± 10.49%, PRB2microg = 73.82 ± 13.49, Kt / V = 1.52 ± 0.28. By scheme at 300ml / min of HD fluid flow: HDFonline xPRU = 81.54 ± 5.25, Standard HD = 78.01 ± 3.03, Daily HD = 60.19 ± 6.71; xPRb2microg HDFonline = 76.70 ± 14.76%, Standard HD 65.44 ± 11.81, Daily HD = 69.16 ± 6.49. Comparing the xPRU at 300ml / min of liquid vs 500ml / min we didn´t found significant differences, nor in the x preHD of urea and B2microglobulin. With the dialysate samples we obtain a polynomial model of order 7 allowing cuantitative adjustment of the curve.R2 0.9, observing in the first 2 hours the greater removing. Conclusions 1. The results are sufficient to consider the result of the removing in each scheme adequate. 2. The decrease in costs would be important (40% of water + energy saving and longer duration elements water treatment. 3. Further study are necessary.

Optimization of the parameters of the piston pin bearing of the tractor engine taking into account the solution of the lubrication problem

The task of the investigation is to make the model, the algorithm, the program and the results of the calculations of optimization of the parameters of the bearing sliding of piston pin of the internal-combustion engine. An approximate mathematical model of dynamically loaded bearings of a piston pin of the internal-combustion engine was built up with the account of calculation methods of the statically loaded sliding bearings. The approximate mathematical model describes the relationship of output parameters of bearings of piston pin the operational and structural factors. The model is based on the method of M.V..Korovchinskiy of hydrodynamic calculation of statically loaded sliding bearings. The solution of optimization task was performed with the help of the author’s program in MATLAB environment. The optimization was produced by using the gradient release method. At each iteration a step was calculated in the condition of minimum of the function of the independent variable. The program of the calculation is a finished product and it can be used at the designing of the bearings of sliding engines.

The Optimization of Small End Bushings of Connecting-Rod in Heavy-Load Diesel Engines

The mechanical fit between the connecting rod's small end and the bush is a typical interference fit. In this paper, an elastic-plastic finite element model of the assembly of the connecting rod and the bush is built based on ABAQUS simulation platform and simulation experiments are carried out by adopting the method of design of experiments. The magnitude of interference and the thickness of the bush are set as the test factors and the maximum radial deformation of the connecting rod’s small end hole, the radial contact pressure between the connecting rod and the bush, the plastic deformation of the bush and the fatigue strength safety coefficient of the connecting rod small end are set as the response variables. Based on the response surface equations, the multi-objective optimal approximate mathematical model is set up and the Pareto optimal set are gained and discussed.

Formulation of Mathematical Modeling to Characterize The Aluminium Metals Using Ultrasonic Non-Destructive Techniques

Predicting the type of aluminium metals and composition of elements present in the aluminium samples through Nondestructive testing (NDT) is a matter of very importance for aluminium Industry. The unique method to determine grade of the aluminium sample is required to characterize the aluminium metals. The Nondestructive Technique (NDT) and determination of characteristics and mechanical properties of aluminium metals are used to identify the grade of aluminium metals so that accordingly it can be used for the specific applications. Therefore a technique is required to predict the percentage of aluminium, Iron, Copper, Manganese of aluminium metals so as to categorize into different grades and applications. In Aluminium samples percentage of Aluminium plays very important role which may help to decide the grade of the aluminium metals hence its applications. The present work is focused on how the percentage of aluminium in aluminium samples can be calculated by adopting the mathematical modeling technique. Â Â There are various parameters which generally affect the percentage of aluminium in aluminium samples, and play a very major role. Therefore through this investigation an attempt is being made to formulate an approximate mathematical model which will certainly predict the percentage of aluminium in aluminium samples. In advent of this a dimensionless pie terms of various prominent parameters or variables have been taken to form a mathematical model. Some of these variables used to formulate this model are given as follows (i) physical properties of the aluminium samples like hardness, density, modulus of elasticity etc (ii) Signal analysis properties like Peak amplitude of Time signal, FFT, PSD and (iii) both the properties. The data of such types of variables have been recorded and calculated and thus the formulation of model is being done by multiple regression analysis. The model is then optimized and the reliability of the model has also been estimated. In fact this type of model will be helpful to estimate the aluminium percentage.