轿车前保险杠注塑过程模拟分析

轿车前保险杠是轿车重要的结构部件,注射成型时,由于注射过程流道长、注射面积大等特点,其制品极易产生气穴、熔接痕及翘曲等注塑缺陷.本文以日本丰田皇冠轿车前保险杠为研究对象,运用Moldflow软件对这种保险杠进行了模拟分析,通过调整塑件的保压压力和保压时间等工艺参数,有效地降低了翘曲变形,提高了产品质量.     

基于Moldflow的薄壁注塑件优化设计

以薄壁注塑件条形码扫描器为例,对其进行分析,对所产生的熔接痕和翘曲变形进行优化,通过修改保压曲线,减少了产品的熔接痕,使翘曲变形量达到了符合的公差要求。     

浇口设计中的CAE优化分析

以电表壳为例分析壳类塑件在注塑过程中最易产生的问题(翘曲变形、熔接痕、气穴),通过Moldflow的模拟过程发现传统模具设计中易导致塑件变形并对其进行优化分析,使产品在设计阶段得到充分优化,缩短产品的开发周期并最终使产品质量(翘曲变形、熔接痕、气穴)得到较大的改善。     

基于Moldflow端盖浇口位置优化设计的研究

浇口位置设计是否合理直接决定了产品成型质量。以某真空机端盖塑件产品为例,基于Moldflow模拟出端盖的最佳浇口位置区域,通过分析结果制定三种浇口位置的方案,利用Moldflow的填充+保压+翘曲模块对不同方案模拟,分别对比三种方案的流动前沿温度、锁模力、熔接痕、总变形量等结果,综合得出方案三最为合理。在很大程度上节省了修模、试模时间,降低模具制造成本,对模具行业大发展有着重要的意义。     

基于MPI的儿童椅塑料件注塑成形预测研究

本文采用MoldfloW(MPI)对儿童椅塑胶制品的注塑成型过程进行了预测,包括浇口位置、充填时间、翘曲变形的大小与产生原因、熔接痕位置、气穴等,为下一步设计及改进模具提出了建议.预测结果表明本产品主要问题是翘曲变形较大,产生翘曲的主要原因是塑胶材料在冷却过程中由不同方向的收缩引起,可以通过改进模具结构、改善成型工艺条件等来减小材料在不同方向的收缩,从而减小翘曲变形.     

注塑件成型工艺参数优化研究

以手机外壳为例,应用CAE软件模拟了注塑件的注塑成型过程。通过正交试验方法与模拟仿真实验的结合,对注塑成型的填充、保压、冷却和翘曲变形过程进行仿真实验分析,获得了制件不同条件下的翘曲变形值。并通过对试验数据的极差分析,得到了不同工艺参数对注塑过程翘曲变形的影响程度,进而得到一组优化的工艺参数组合,同时对优化后的工艺参数组合进行仿真模拟分析,得到了符合产品要求的翘曲变形量,为同类制品的工艺参数优化提供了依据。     

大型薄壁塑件翘曲变形分析及工艺参数优化

在注塑成型大型薄壁塑料产品过程中,由于熔料流动路程长,流动阻力大,产品极易产生翘曲变形,从而影响到使用性能.应用Moldflow软件分析了影响产品翘曲变形的主要原因是收缩率不均引起.通过优化工艺参数,即优化保压曲线,减小了产品翘曲变形.方珐是将保压设置由恒压保压调整为先恒压再线性递减的两段保压,然后再多次调整保压曲线各...     

基于Moldflow的塑料拉手注射模具设计

介绍了一种塑料拉手注射模具的设计和工作过程,应用Moldflow软件分析了不同的浇口位置、气穴位置及熔接痕分布、翘曲变形量等的影响,Moldflow分析结果说明了在塑料模具优化设计中具有很好的可靠性。     

基于Moldflow分析的汽车前保险杠注塑模浇注系统优化设计

以某汽车前保险杠为研究对象,利用Moldflow软件对不同浇注系统设计方案的填充时间、注射压力及锁模力、熔接痕和气穴等分析结果进行比较,确定了浇注系统的优化方案,从而有效降低了生产成本,缩短了产品开发周期,提高了模具设计效率。     

汽车格栅制品的常见缺陷及解决办法

对汽车通风格栅这种塑料制品在成型的过程中容易产生的填充不足、熔接线/熔接痕、气穴、翘曲、溢料飞边等五种最为常见的缺陷进行了分析,阐述了影响格栅制品成型质量的主要因素,最后提出了防止质量缺陷的产生,获得高质量的格栅制品的措施。     

Study on arc characteristics and their influences on weld bead geometry in narrow gap GMAW of 5083 Al-alloy

As an efficient process, narrow gap gas metal arc welding (NG-GMAW) was employed to join thick plates of 5083 Al-alloy. In this paper, arc characteristics in NG-GMAW of 5083 Al-alloy and their influence on the weld bead geometry were studied with synchronous acquisition system for various groove types, welding modes, welding current levels, and swing frequencies. The arc profiles were measured and appear to be entirely different compared with that in bead-on-plate GMAW process, meanwhile the arc size changes with varied welding mode, welding current, and arc swing frequency. Arc characteristics highly affect the weld bead geometrical parameters such as bead width, welding penetration, sidewall penetration, and weld surface concavity. Linear regressions were made between the arc characteristics and the weld bead geometrical parameters both in swing and non-swing arc process. It showed that a negative linear correlation exists between welding penetration and arc length, sidewall penetration, and arc warpage, while a positive linear correlation exists between weld surface concavity and arc warpage in non-swing arc process. In contrast, a non-linear correlation exists among them and the variation tendency remains the same in swing arc process.     

Modeling of friction-stir butt-welds and its application in automotive bumper impact performance Part 2. Impact modeling and bumper crash performance

Ever increasing requirements regarding vehicle safety have led to rapid developments in various joining process. Among FSW widely used for Aluminum alloy welded structure of car body because of their remarkable performance in welding. For a better understanding of this performance, it is necessary to determine the behavior of butt weld in service conditions. In earlier phase of this study, thermo mechanical simulations and analysis are performed to understand the thermal behavior in the FSW weld zones. The developed models are correlated against published experimental results in terms of temperature profile of the weld zone. The objectives of the second part of this work is to develop and demonstrate an FE model of bumper and crash box assembly that would improve on the current modeling techniques for the mechanical response of welds in structural problems.     

注塑件翘曲量化分析与成形工艺优化方法研究

针对注塑件有限元翘曲分析存在的整体量化与工艺参数优化问题,通过二次开发实现了注塑件翘曲的综合量化。结合正交实验设计,得出影响翘曲大小的工艺参数贡献度,从而获得多参数优化组合,实现了注塑件翘曲优化。     

Injection molding optimization with weld line design constraint using distributed multi-population genetic algorithm

Weld lines not only detract from an injection-molded part??s surface quality, but also significantly reduce its mechanical strength. It is not always easy to completely eliminate weld lines by simply adjusting the relevant injection mold design or the molding conditions. One solution is to prevent the weld lines from forming in regions that are structurally or aesthetically sensitive. The influence of weld lines on the quality of injection-molded parts cannot be overlooked and weld lines should be regarded as an important design constraint, especially for parts with aesthetic concerns. Since precisely predicting the number of weld lines and their positions and lengths is difficult without executing simulation routines, especially when part geometry is considered a design variable, this study adopts an enhanced genetic algorithm, referred to as distributed multi-population genetic algorithm (DMPGA), combining an optimization algorithm and commercial MoldFlow software with a dominance-based constraint-handling technique and a master?Cslave distributed architecture. MoldFlow obtains relevant data regarding warpage and weld lines and evaluates the corresponding designs. The dominance-based constraint-handling technique handles the weld line design constraint without needing additional penalty factors. Finally, the master?Cslave distributed architecture reduces the formidable computational time required for injection molding optimization. To illustrate the high viability of DMPGA, this study provides an outer frame of a digital photo frame as an optimization example. The results of this study show that DMPGA cannot only effectively decrease maximum part warpage without violating the weld line constraint, but also conquer hurdles attributed to constraint handling and computational demand.     

基于Moldflow的塑料碗注塑模设计

以塑料碗的注塑模设计为例,借助模流分析软件Moldflow对其充模时间、注射压力、体积收缩、气穴和熔接痕等进行模拟分析,根据结果有针对性地优化模具设计方案,从而可以提高制品质量,缩短模具设计制造和产品开发周期.     

An effective warpage optimization method in injection molding based on the Kriging model

In this paper, an effective optimization method using the Kriging model is proposed to minimize the warpage in injection molding. The warpage deformations are nonlinear, implicit functions of the process conditions, which are typically evaluated by the solution of finite element (FE) equations, a complicated task which often involves huge computational effort. The Kriging model can build an approximate function relationship between warpage and the process conditions, replacing the expensive FE reanalysis of warpage in the optimization. In addition, a “space-filing” sampling strategy for the Kriging model, named rectangular grid, is modified. Moldflow Corporation’s Plastics Insight software is used to analyze the warpage deformations of the injection-molded parts. As an example, the warpage of a cellular phone cover is investigated, where the mold temperature, melt temperature, injection time, and packing pressure are regarded as the design variables. The result shows that the proposed optimization method can effectively decrease the warpage deformations of the cellular phone cover and that the injection time has the most important influence on warpage in the chosen range.     

Experimental evaluation and simulation of volumetric shrinkage and warpage on polymeric composite short natural fibers reinforced injection molded

A polymeric natural fiber-reinforced composite is developed by extrusion and injection molding process. The shrinkage and warpage of high-density polyethylene reinforced with short natural fibers of Guadua angustifolia Kunth are analyzed by experimental measurements and computer simulations. Autodesk Moldflow® and Solid Works® are employed to simulate both volumetric shrinkage and warpage of injected parts at different configurations: 0 wt.%, 20 wt.%, 30 wt.% and 40 wt.% reinforcing on shrinkage and warpage behavior of polymer composite. Become evident the restrictive effect of reinforcing on the volumetric shrinkage and warpage of injected parts. The results indicate that volumetric shrinkage of natural composite is reduced up to 58% with fiber increasing, whereas the warpage shows a reduction form 79% to 86% with major fiber content. These results suggest that it is a highly beneficial use of natural fibers to improve the assembly properties of polymeric natural fiber-reinforced composites.     

注射模工艺参数对塑件翘曲量的影响及优化

利用Moldflow分析软件,采用数值模拟的方法分析了料温、模具温度、注射时间、冷却时间和保压压力等工艺参数的变化对塑件产品翘曲的影响趋势及其原因。结果表明:对所选参数,保压压力对塑件翘曲的影响最为显著,且保压压力取注射压力的95%左右可使产品的翘曲量达到较小的程度;产品翘曲量随料温升高,注射时间减短而减小;冷却时间对翘曲量的影响甚微;模具温度对翘曲影响较为复杂。根据分析结果,优化了塑件的成型工艺参数,使得翘曲量进一步减小。     

A development of simple analysis model on bumper barrier impact and new IIHS bumper impact using the dynamically equivalent beam approach

This paper presents a simple analysis model for bumper barrier impact and new IIHS (Insurance Institute for Highway Safety) bumper impact instead of a non-linear finite element impact analysis. A dynamically equivalent beam approach was introduced to simplify the non-linear dynamic bumper impact. For a bumper barrier impact, the equivalent curved-beam element was substituted for the bumper beam and the bumper foam. For a new IIHS bumper impact, a modified curved-beam element of bumper barrier impact considering the effect of contoured new IIHS impact barrier was used. The accuracy of this simple analysis model was tested by comparing its results with those of the non-linear finite element analysis. Tested bumper beam types were press type beam and roll forming beam used widely in the current car bumpers. The maximum displacement error between the two models did not exceed 1.95% for a barrier impact and 13.2% for a new IIHS bumper impact. This accuracy is good enough to be used in the early stage of bumper beam design process. This simple analysis model is expected to reduce the car development time and tests cost significantly.