Door sealing mechanism and process in vehicle engineering

The reliability of door sealing plays an important role in maintaining the quality of vehicle noise, vibration, and harshness (NVH). To improve the reliability of door sealing, a novel sealing process has been proposed. The factors influencing the door sealing quality have been investigated. The relationships between the peeling force, peeling speed, and peeling time have been calculated using the five-variable rheological theory. The maximum stress versus time curve and the distribution of stress and strain at the moment of debonding have been obtained by nonlinear solid cohesive coupling dynamics simulation. The rolling process of the door sealing strip has been developed, and automatic rolling equipment for door sealing has been designed and manufactured. The factors influencing the peeling force have been determined by a peeling test of the door sealing strip. The results show that the peeling force increases with an increase in the peeling speed and time. The C-shaped structure at the front end of the base material during the stripping process makes the peeling angle sharp. In addition, the uneven stripping speed causes the stripping line to become irregular. The peeling force increases with the increase in rolling pressure and failure time. The optimum rolling pressure was 70 N/m2 and the optimum aging time was 24 h.

Surface topography after deep rolling with milling kinematics

Deep rolling is a machining process which is used to decrease roughness and to induce compressive residual stresses into component surfaces. A recent publication of this research group showed possibilities to predict the topography during deep rolling of bars in a lathe. Although deep rolling can be used in a milling machine to machine flat specimens, it is still unclear, whether the topography can be predicted to a similar extend using this application. To investigate the influence of the machining parameters on topography, three experimental stages are performed in this paper on cast AlSi10Mg. First, single-track deep rolling experiments are performed under variation of the deep rolling pressure $$p_w$$ p w to find the relationship between $$p_w$$ p w and the indentation geometry. Here, a logarithmic relationship between deep rolling pressure and the indentation characteristics could be found that achieved a relatively high agreement. In the second stage, surfaces are prepared using multi-track deep rolling. Here, the deep rolling pressure $$p_w$$ p w and the lateral displacement $$a_b$$ a b are varied. The multi-track rolled surfaces were compared to an analytical model for the calculation of the theoretical roughness that is based on the logarithmic relationship found in the first experimental stage. Here, the limits of the analytical prediction were shown because high similarities between predicted and measured surfaces only occurred for certain deep rolling pressures $$p_w$$ p w and lateral displacements $$a_b$$ a b . To further investigate the limitations of this procedure, a novel tool concept, which utilizes the rotation of the machine spindle, is used in the third stage. Here, the generated surface can also be interpreted as a periodic sequence of spheric indentations as shown in the second experimental stage, whereas the measured surfaces differed from the expected surfaces. As a result of this paper, the predictability of the surface topography after deep rolling of flat specimens is known (minimum pressure $$p_{w,minAlSi10Mg}$$ p w , m i n A l S i 10 M g = 5 MPa and minimum lateral displacement $$a_{b,minAlSi10Mg}$$ a b , m i n A l S i 10 M g = 0.25 mm) and also first results regarding the final topography after using the novel tool concept are presented.

INFLUENCE OF TECHNOLOGICAL PARAMETERS ON CHARACTERISTICS OF POLYMER COMPOSITE MATERIALS IN AUTOMATED LAYUP OF PREPREGS (review)

The main technological factors when using ATL and AFP technologies are material temperature, laying speed, rolling pressure and no deviation from the required laying trajectory. The article discusses the influence of technological factors on some characteristics of polymer composite materials. The optimum laying temperature should provide the required adhesion. The rate of laying should provide heating of the material without its technological properties. The rolling pressure during laying should ensure optimal porosity and thickness of the material.

Influence of Deep Rolling Process Parameters on Surface Residual Stress of AA7075-T651 Aluminum Alloy Friction Stir Welded Joint

Friction stir welding is most commonly used for joining aluminum alloy parts. After welding, residual stresses occurred in the welded joint caused by non-uniform cooling rate. Friction stir welding usually generates tensile residual stress inside the workpiece which affects the strength in addition to the fatigue life of materials. Compressive residual stress usually is beneficial and it can be introduced by mechanical surface treatment methods such as deep rolling, shot peening, laser shock peening, etc. In this research, deep rolling was used for inducing compressive residual stress on surface of friction stir welded joint. The residual stresses values were obtained from X-ray diffraction machine. Influence of three deep rolling process parameters: rolling pressure, rolling speed and rolling offset on surface residual stresses at the welded joint were investigated. Each factor had 2 levels (23 full factorial design). The statistical analysis result showed that the rolling pressure, rolling speed, rolling offset, interaction between rolling pressure and rolling speed, interaction between rolling speed and rolling offset were statistically significant factors, with the most compressive residual stress value approximately -391.6 MPa. The appropriated deep rolling process parameters on surface residual stress of AA7075-T651 aluminum alloy friction stir welded joint were 1) rolling pressure about 150 bar 2) rolling speed about 1,400 mm/min 3) rolling offset about 0.1 mm.

Effects of Deep Rolling on Surface Residual Stress and Microhardness of JIS SS400 MIG Welding

Metal Inert Gas (MIG) welding process is a common welding process for carbon steels. During the cooling after welding, non-uniform cooling cause tensile residual stress on the surface of welded joint and, in most cases, in Heat Affected Zone (HAZ) also. The tensile residual stress is undesirable because it affects the strength and shorten the workpiece fatigue life. In order to convert the tensile residual stresses to desirable compressive residual stresses, the mechanical surface treatment like deep rolling process was used in this research. The surface residual stresses were measured by XRD machine with the sin2ψ method. For statistical analysis of significant factors used in deep rolling process, there are three factors each factor has two levels: rolling pressure, rolling speed and number of passes. Taguchi experimental design was used in conjunction with a deep rolling process to determine factors affected the surface residual stresses and surface microhardness. The results of the research showed that the most significant factors that affect the surface residual stress and surface microhardness were the number of passes, followed by the rolling pressure and the rolling speed, respectively. The maximum compressive residual stress measured at the welded joint was -521.5 MPa. The highest measured surface microhardness was 266.2 HV at the welded joint. The appropriated factors of deep rolling process for JIS SS400 MIG welding were rolling pressure 270 MPa, rolling speed 1,500 mm/min and number of passes 3 times.

Study on Recrystallization Behaviour of Hot Medium Plate Rolling

The effect regulation of recrystallization softening on rolling load of 16MnR plate hot rolling was studied by means of researching theory analysis and experiment model based on the simulation of the austenitic recrystallization of 16MnR plate hot rolling. The results show that it is static recrystallization totally and almost partial static recrystallization in pass of 16MnR plate hot rolling, the measurement results are in accordance with the prediction value of consideration the effect of recrystallization softening on rolling load of 16MnR plate hot rolling, the Sims equation is suitable for calculating the rolling pressure of the pass after complete recrystallization softening of plate hot rolling.

Analyzing Rolling Pressure of Rolling Strip by Multi-Object Contact Multi-Pole Boundary Element Method

For guiding production effectively and revealing rolling mechanisms, the analysis of rolling-pressure distribution regulation is very important. Because rolling strip belongs to multi-object contact engineering problem which involves coupling deformation, obviously the accuracy of disaggregate mathematical method is low. Therefore, in this paper,it is developed that multi-object, elasto-plastic and frictional contact multipole Boundary Element Method (BEM) by Fortran program. It can simulate five object synchronous contact accurately without artificial assumption.The three dimensional rolling-pressure distribution regulation of rolling strip has been obtained through this program. Through testing and calculating the load properties of bearing, the result shows that it is accordant for test and calculation. Therefore, multi-pole BEM is one of the effective numerical analytic tools of rolling contact problem, and the obtained result of rolling-pressure distribution can provide for reference value for analyzing rolling strip.