Application of bird-strike verified analysis for the design of fast helicopter composite cowling

PurposeThe purpose of this paper is to describe the approach for the design of a jet engine composite air inlet for a new generation of jet trainer aircraft from the perspective of airworthiness requirements regarding high-speed impact resistance.Design/methodology/approachValidated numerical simulation was applied to flat test panels. The final design was optimised and verified by validated numerical simulation and verified by testing on a full-scale demonstrator. High-speed camera measurement and non-destructive testing (NDT) results were used for the verification of the numerical models.FindingsThe test results of flat test panels confirmed the high durability of the composite structure during inclined high-speed impact with a near-real jet inlet load boundary condition.Research limitations/implicationsOwing to the sensitivity of the composite material on technology production, the results are limited by the material used and the production technology.Practical implicationsThe application of flat test panels for the verification and tuning of numerical models allows optimised final design of the air inlet and reduces the risk of structural non-compliance during verification tests.Originality/valueNumerical models were verified for simulation of the real composite structure based on high-speed camera results and NDT inspection after impact. The proposed numerical model was simplified for application in a real complex design and reduced calculation time.

In seismic analysis, vertical component of the earthquake due to the impact on fluid sloshing in a tank and intensifying of P-delta effects is of particular importance. In order to investigate the performance of the tank and the impact of the fluid surface sloshing, harmonic frequencies were applied to a tank of of water with 60 cm in diameter and different depths of water. Different frequencies were applied to the tank by an innovative tool. Abacous is a structural soft-ware which is capable to model numerically the interaction of structure and fluid. Verification and calibration of numerical model was performed by comparing water level fluctuations in experimental and numerical models. Different combinations of parameters such as hourglass coefficient, methods of grid generations and the cell sizes in numerical model were performed to obtain the consistent results with experiments. The results of numerical modeling had a correlation factor of 98% with laboratory results. Then, the numerical model of elevated tanks with large scales were created in software The numerical model of elevated tanks with three different ratios of fluid depth and tank radiuses to the tank height were created and modeled by software. The angle of the floor in all tanks was 45 degrees. Each case was evaluated by7 different mapping acceleration from different earthquakes. In all cases the effect of vertical component of earthquake, the wave height and moment in foundation were investigated. The results showed that the vertical component of the earthquake resulted in an increase of 38% in the height of water and 9% increase in the moment of foundation.

Scope Advanced Non Destructive Testing (NDT) techniques rely on consistent acquisition of data and its reliable analysis. As technology advances, new challenges emerge. For instance, the amount of data produced is exceeding the qualified personnel available for data analysis; moreover, the files produced can be easily handle unethically. Our project proposes the implementation of Artificial Intelligence (AI) techniques to develop algorithms to better harness the data available, in order to enhance the quality of data analysis and better monitor ethical practices. Method: For any NDT technique, the consistency of the results and the reliability of the findings depends heavily on the personnel performing the inspections and evaluating the results. As more advanced NDT techniques are available in the areas of ultrasound, digital data becomes available opening the door for intelligent tools for analysing and handling ultrasound data. This project proposes an innovative analysis software based on Computational Intelligence (CI) techniques. The implementation of this software reduces the time needed for a single analysis and the consistency of results, more importantly; it can be use as an audit tool to ensure data files have not been mishandle. Results/conclusions For the first stage of the proposed CI cloud-based software, the data collected by the inspector is send via internet connection to web-based servers. During the second stage, the data will be verify for quality; if any data is missing or poor-quality is detected, the software will inform the inspector that data must be resubmitted. Once the verification of data is completed, the data analysis is then perform by CI-based algorithms, which can recognise and classify features within the data such as geometry indications, anomalies and defects. Following the CI-based analysis, the software generates a complete report and the results are be available to the user via a 3D visualization interface. This report includes details of sizing, characterisation, location of defects, geometry indications and other relevant information related to the analysed data. The information contained in the interface and generated by the software will be available to the final user for validation and approval. The CI-based analysis tools have already been use to monitor several data files from NDT inspections using Phased Array Ultrasound (PAUT) and the results have successfully verify the authenticity of the ultrasound raw data, which is a critical verification step and evidence of any mal practices or mistakes of data handling. Novelty There is a lack of reliable tools available to NDT experts that can facilitate the task of analysing data; this innovative software takes advantage of the CI techniques and expert knowledge to address this issue. Furthermore, our approach offers a high degree of consistency for identifying defects; improves the quality of the analysis and reduces the time invested in such critical NDT duty. Auditing raw data from ultrasound inspection is a challenging task; by taking advantage of CI-based analysis tools this task can be easily implement it as reliable auditing practice.

The use of robotics is beginning to play a key role in automating the data collection process in Non Destructive Testing (NDT). Increasing the use of automation quickly leads to the gathering of large quantities of data, which makes it inefficient, perhaps even infeasible, for a human to parse the information contained in them. This paper presents a solution to this problem by making the process of NDT data acquisition an autonomous one as opposed to an automatic one. In order to achieve this, the robotic data acquisition task is treated as an optimisation problem, where one seeks to find locations with the highest indication of damage. The resulting algorithm combines damage detection technology from the field of data-driven Structural Health Monitoring (SHM) with novel ideas in uncertainty quantification which enable the optimisation routine to be probabilistic. The algorithm is sequential; a decision is made at every iteration regarding the next optimal physical location for making an observation. This is achieved by modelling a two-dimensional field of novelty indices across a part/structure which is derived from a robust outlier analysis procedure. The value of this autonomous approach is that the output is not only measured data, but the most desirable information from an NDT inspection – the probability that a component contains damage. Furthermore, the algorithm also minimises the number of observations required, thus minimising the time and cost of data gathering.

Technological advances in the nondestructive evaluation of Oil Country Tubular Goods (OCTG) have brought about enhanced methods to minimize risk factors associated with the drilling or transport of oil and natural gas. This paper focuses on a multidimensional, nondestructive testing (NDT) inspection and measurement package combining wall thickness and outer diameter (OD) measurement data into a single inspection report per tubular. This method of dimensional measurement is performed on the front end of a project, providing end users with numerous benefits from a cost and time perspective, as well as the critical data needed to optimize operations. The package provides high-resolution inspection data for the manufacturer or end user, yielding higher precision burst and collapse strength predictions than previously available. Other benefits of this method include optimization of material placement in casing string design, estimation of cementing fluid volume, and downhole tool clearances among other applications. Confidence and safety levels of burst and collapse ratings are of particular interest to drilling engineers. The wall thickness variations and tubular eccentricity are measured using an automated, nondestructive ultrasonic testing system, utilizing compression wave transducers. The OD measurement is acquired using an automated, nondestructive laser-based testing system. Laser-based testing uses two laser-scan micrometers positioned horizontal to the tubular and 180° apart (Fig. 1). Each laser measures the distance between the tubular and the receiver. These two measurements are combined to calculate the tubular OD. The level of accuracy provided by this technology continues to push the industry forward with higher quality tubulars ranging from the mills to end users.

To comprehensively explore the utility of non-destructive tests (NDT) results for structural diagnosis, this study collected NDT results and core compressive strength test results from aged bridges. Girders and slabs were obtained from seven such bridges, and after sectioning, rebound hardness test (RHT) or ultrasonic pulse velocity test (UPVT) were conducted alongside coring. The standard equations for estimation in South Korea were applied and a comparison between core strength and strength estimated using NDT results was conducted. In addition, the relationship between the static modulus and core specimen strength was determined to assess the soundness of the concrete cores, a factor that influences NDT signals. Based on the experimental results, this study deliberates on the practical applications of NDT results in structural diagnosis. A protocol for calculating the characteristic in-situ compressive strength using NDT results without coring was proposed and statistically validate this protocol via a probabilistic simulation.

High-speed impact on spacecraft by space debris poses a threat. When a high-speed projectile collides with target, it is conceivable that the heat created by impact causes severe damage at impact point. Investigation of the temperature is necessary for elucidation of high-speed impact phenomena. However, it is very difficult to measure the temperature with standard methods for two main reasons. One reason is that a thermometer placed on the target is instantaneously destroyed upon impact. The other reason is that there is not enough time resolution to measure the transient temperature changes. In this study, the measurement of plasma induced by high-speed impact was investigated to estimate temperature changes near the impact point. High-speed impact experiments were performed with a vertical gas gun. The projectile speed was approximately 700 m/s, and the target material was A5052. The experimental data to calculate the plasma parameters of electron temperature and electron density were measured by triple probe method. In addition, the diffusion behavior of plasma was observed by optical visualization technique using high-speed camera. The frame rate and the exposure time were 260 kfps and 1.0 μs, respectively. These images are considered to be one proof to show the validity of plasma measurement. The experimental results showed that plasma signals were detected for around 70 μs, and the rising phase of the wave form was in good agreement with timing of optical visualization image when the plasma arrived at the tip of triple probe.

Analysis of the single and combined non-destructive test approaches for on-site concrete strength assessment: General statements based on a real case-study

An experimental study on non-linear progressive wave-induced dynamic stresses in seabed

Experimental and numerical investigation of lightweight foamed reinforced concrete deep beams with steel fibers

Salinization of land and water is a significant challenge in most continents and particularly in arid and semi-arid regions. The need to accurately forecast surface and groundwater interactions has promoted the use of physically-based numerical modelling approaches in many studies. In this regard, two issues can be considered as the main research challenges. First, in contrast with surface water, there is generally less observed level and salinity data available for groundwater systems. These data are critical in the validation and verification of numerical models. The second challenge is to develop an integrated surface-groundwater numerical model that is capable of salt mobilization modelling but which can be validated and verified against accurate observed data. This paper reviews the current state of understanding of groundwater and surface water interactions with particular respect to the numerical modelling of salt mobilization. 3D physically-based fully coupled surface-subsurface numerical model with the capability of modelling density-dependent, saturated-unsaturated solute transport is an ideal tool for groundwater-surface water interaction studies. It is concluded that there is a clear need to develop modelling capabilities for the movement of salt to, from, and within wetlands to provide temporal predictions of wetland salinity which can be used to assess ecosystem outcomes.

Experimental and numerical investigations of perforated CFR woven fabric laminates

Multivariate randomized block permutation procedures (MRBP) can be used effectively to verify numerical models. Compared to other statistical methods, MRBP shows several distinct advantages. First of all, MRBP operates in the same Euclidean analysis space as its input data. The root mean square error (RMSE) is discussed, since it is a natural choice as a distance measure between two data sets and is closely related to the distance measure on which MRBP is based. The RMSE by itself provides no basis for inferential comparisons, whereas MRBP is well suited for such deductions. Since MRBP is computationally economical and requires only a few case studies for meaningful comparisons, it is also useful for model development.

This paper presents ongoing research in behaviour of laterally unrestrained beams (I or H section) of Class 4 cross-sections at elevated temperatures, which is based on the RFCS project FIDESC4 - Fire Design of Steel Members with Welded or Hot-rolled Class 4 Cross-sections. Despite the current EC3 contains a number of simple rules for design of slender Class 4 cross-sections at elevated temperature, based on recent numerical simulations they were found to be over-conservative. Therefore, new well representing design models, which simulate the actual behaviour of the structures exposed to fire, are crucial. These design rules should be based on extensive numerical simulation validated on experimental data. Within this task, several tests were carried out to study lateral torsional buckling of Class 4 beams in fire. The design of the test set-up and description of the experiment is given, as well as verification of numerical model.

The verification and validation of CFD software is of utmost importance for the reliability and hence for the success of CFD technology in industry. This paper discusses the relative importance, key elements, and some examples of: • Verification of numerical models and computer software; • Validation of solutions against benchmark data; and • Calibration of the models and analysis process. Out of these, the main emphasis is placed on verification. This is in light of the growing generality and complexity of CFD software (in response to continuously increasing expectations in industry). Finally, three key success factors for effective utilization of CFD technology are pointed out. These are: 1) Verifications and Validation of software; 2) Skills of the Users; and 3) Vision, and commitment of the manager (s).