Method of effective evaluation for examination of chloride ion in concrete

The chloride ion contained in reinforced concrete seriously corrodes the steel surface and damages concrete, resulting in inferior reinforced concrete that strength seriously compromises the entire structure’s safety. Consequently, the examination of chloride ions contained in reinforced concrete becomes an important part of a complete quality control procedure. To effectively check the concentration of chloride ions in concrete, the evaluation process should be accurate and precise. Laboratory data ob- tained using existing evaluation methods for the examination of chloride ion are not sufficiently objective to yield reliable results with accuracy and consistency for each sample. An evaluation algorithm with capability to define indices of precision degree (Ep) and accuracy degree (Ea) is presented in this paper. The authors established a statistically reliable index of unbiased estimators and equations to critically examine the laboratory methods’ precision, accuracy degrees and application value for measuring chlorine ion concentration in reinforced concrete.

Analysis modeling for plate buckling load of vibration test

In view of the recent technological development, the pursuit of safehigh-precision structural designs has been the goal of most structural designers. To bridge the gapbetween the construction theories and the actual construction techniques, safety factors are adoptedfor designing the strength loading of structural members. If safety factors are too conservative,the extra building materials necessary will result in high construction cost. Thus, there has been atendency in the construction field to derive a precise buckling load analysis model of member inorder to establish accurate safety factors. A numerical analysis model, using modal analysis toacquire the dynamic function calculated by dynamic parameter to get the buckling load of member, isproposed in this paper. The fixed and simple supports around the circular plate are analyzed by thisproposed method. And then, the Monte Carlo method and the normal distribution method are used forrandom sampling and measuring errors of numerical simulation respectively. The analysis resultsindicated that this proposed method only needs to apply modal parameters of 7 X 7 test points toobtain a theoretical value of buckling load. Moreover, the analysis method of inequality-distanttest points produces better analysis results than the other methods.

Time domain system identification of unknown initial conditions

System identification is a method for using measured data to create or improve a mathematical model of the object being tested. From the measured data however, noise is noticed at the beginning of the response. One solution to avoid this noise problem is to skip the noisy data and then use the initial conditions as active parameters, to be found by using the system identification process. This paper describes the development of the equations for setting up the initial conditions as active parameters. The simulated data and response data from actual shear buildings were used to prove the accuracy of both the algorithm and the computer program, which include the initial conditions as active parameters. The numerical and experimental model analysis showed that the value of mass, stiffness and frequency were very reasonable and that the computed acceleration and measured acceleration matched very well.

Analytical method for promoting process capability of shock absorption steel

Mechanical properties and low cycle fatigue are two factors that must be considered in developin gnew type steel for shock absorption. Process capability and process control are significant factors in achieving the purpose of research and development programs. Often-used evaluation methods failed to measure processyield and process centering ; so this paper uses Taguchi loss function as basis to establish an evaluation methodand the steps for assessing the quality of mechanical properties and process control of an iron and steel manu-facturer. The establishment of this method can serve the research and development and manufacturing industry and lay a foundation in enhancing its process control ability to select better manufacturing processes that are more reliable than decision making by using the other commonly used methods.