The laser forming process is an emerging area of research and industry, primarily focused on materials like titanium, magnesium, steel, and their alloys. However, aluminum alloys have received less attention due to challenges related to surface reflection and low absorption coefficients.In this research, the effect of different process parameters on bending angle in the laser bending of Al 6061 sheets was investigated by experiments and finite element simulation. The parameters were optimized by Response Surface Method (RSM) to achieve the maximum bending angle. In addition, the reproducibility of the process, as well as the accuracy and validation of the simulation, were examined by conducting experiments that involved accurate measurement of the bending angle. The results revealed that the sheet thickness had the most significant effect on the bending angle. Specifically, with an increase of 1 mm in the sheet thickness, the bending angle decreased by 77%. Additionally, through process parameter optimization, the maximum bending angle achieved was 4.911 degrees.

Laser tube bending is a flexible forming process. Two irradiation methods of axial and circumferential scanning are generally used to form metal tubes. The two most important disadvantages of circumferential scanning are its lower bending angle and the time interval required between each scan for cooling purpose. In this research, a novel cooling strategy during laser tube bending with circumferential scanning is proposed to eliminate these disadvantages. The effects of this method on the bending angle and total production time are experimentally investigated. Also, the changes in the microstructure of the tube after bending are studied. The bending angle obtained at each scan using this strategy was increased more than 1. 5 times with much less production time and energy consumption. Besides, the undesired effect of HAZ was significantly reduced. It is shown that this new cooling technique can highly improve the efficiency of laser tube bending by the circumferential scanning method.

The relationship between the flexural rigidity of standard warp knitted fabrics and fabric and yam parameters, such as wale and course spacing, underlap length of the front and back guide bars, yam bending rigidity, etc., is discussed. In this study, a mechanical model for the bending behaviour of the warp knitted fabrics is also presented. In theoretical analysis, the knitted fabric loop structure is assumed to consist of a series of straight and skew yam simulating legs and underlaps. The estimation of fabric bending rigidity is based on summing up the bending rigidity of the straight and skew yams that found by energy method with taking into account of rigid region lying in the direction of bending. The estimated values from this model are compared with experimental results obtained on a developed automatic cyclic pure bending tester.Comparison with experimental and theoretical data shows reasonable agreement between predicted and measured flexural rigidity of warp knitted fabrics.

Nowadays thin-walled tube rotary draw bending in small bending ratio is a production process widely used in advanced industries such as aerospace and automotive. Cross section ovality, wall thickness changing during tube bending are the main inevitable defects in this process. The purpose of this research is to obtain the smallest bending ratio and maximum pressure applicable in hydro-rotary draw bending of thin-walled aluminum alloy 8112 tube using failure criterion. For this purpose, the equivalent plastic strain at the critical extrados region is used for necking prediction. Concluded results showed that this failure criterion by a maximum difference of 12.5% from experimental tests, is a useful method for predicting the necking onset in the bending process. Moreover, the effects of bending ratio and internal pressure on the defects such as cross section ovality and changes in thickness are investigated with simulation in the ABAQUS software and experimental methods. The maximum ovality is not located at the mid-cross section of bent tube unexpectedly and regardless of the internal pressure and bending ratio, occurs at the cross-section with an angle of approximately q=33o. The minimum achievable amounts of ovality at R/D1.6, R/D1.8 and R/D2 were 11.42%, 7.72% and 4.35% respectively. Furthermore, bending ratio and internal pressure had noticeable effects on the cross section of the bent tubes, so that as the bending ratio or pressure increased, cross-section ovality and the thickening of the tube wall at the intrados decreased, but contrary to bending ratio, as the internal pressure increased, extrados thinning increased.

One of the most prominent processes in industry is bending. Rotary draw bending method is known to be the most conventional approach for thin wall tube bending. Pressure die is an effective tool which boosts the tube bending process and eventually improves the bending quality. Other effective parameters include mandrel and the amount of clearance between tube and mandrel. In the present study, the process was modeled by finite element method and the precision of the model was validated via comparing practical results. Subsequently, using the validated model, the effects of pressure die movement and the mandrel and its clearance were investigated. Specifically, the force vicissitudes and bending quality with respect to mandrel clearance and pressure die movement were evaluated. It was shown that reducing the clearance between mandrel and tube, results in force increase while the bending quality was improved. Also it was indicated that the pressure die movement has less effects on process forces and flattening the tube.

In this paper an analytical model for prediction of angular deformation is presented. In this model convective heat losses and a multipoint distributed heat source is used for determination of the inherent strain zone which causes the bending angle. The effects of laser bending process parameters including laser power, beam diameter, scan velocity and pulse duration on the bending angle were investigated experimentally. Main effects of factors were considered and the regression line was derived. An L9 Taguchi’s standard orthogonal array was employed as experimental design and the level of importance of the laser bending process parameters on the bending angle was determined using analysis of variance (ANOVA). Comparison of the analytical model and experimental results has shown a reasonable agreement.

In seismic areas, ductility is an important factor in the design of high strength concrete (HSC) members under flexure. In order to investigate this, here in this study, eight HSC beams with different percentages of  r & r’ were cast and incrementally loaded under bending. During the test, the strain on the concrete middle faces, the tension and compression bars, and also the deflection at different points of the span length were measured up to failure. Based on the obtained results, the serviceability and ultimate behavior, and especially the ductility of the HCS members are more deeply reviewed. Also a comparison between theoretical and experimental results is reported here.

Laser Forming (LF) process is one of the thermal forming processes, which uses laser beam irradiation as a forming factor. In this process, temperature gradient along the sheet thickness produces the final bending angle. So far, various investigations are carried out on laser forming of low carbon steel sheets. However, LF process can be utilised in other metallic and non-metallic sheets. High surface reflectivity and thermal conductivity of aluminium sheets, compared to steel sheets, make them more difficult and more complicated to be laser formed than that of steel sheets. In this Article, using LF process simulation with the finite element software, effects of several process parameters such as laser power, scan speed, laser beam diameter and sheet thickness on final bending angle are investigated. Numerical results are validated with the same parameter assigned experimental results. This comparison shows a very good accordance between simulation and experimental results. Also, an equation is derived to predict the final bending angle correspond to the variations of mentioned parameters. This is derived by the use of Design of Experiment (DOE) and full factorial approach.