【摘要】：物流中,振動(dòng)與沖擊等惡劣環(huán)境會(huì)造成產(chǎn)品破損。在優(yōu)化改進(jìn)產(chǎn)品自身結(jié)構(gòu)的同時(shí),緩沖包裝也是產(chǎn)品防護(hù)的重要組成部分,設(shè)計(jì)可靠的包裝結(jié)構(gòu)可以有效降低振動(dòng)與沖擊對(duì)產(chǎn)品的損壞。然而,目前物流中惡劣環(huán)境下產(chǎn)品防護(hù)動(dòng)力學(xué)研究較為薄弱,產(chǎn)品的包裝設(shè)計(jì)缺乏深入和有效的理論支持與指導(dǎo)。各種實(shí)際緩沖包裝件可以統(tǒng)一抽象為緩沖包裝系統(tǒng),各種型式包裝系統(tǒng)在各種典型激勵(lì)下的動(dòng)力學(xué)響應(yīng)特性是緩沖包裝設(shè)計(jì)的理論依據(jù)。緩沖系統(tǒng)的響應(yīng)既取決于環(huán)境作用的力或運(yùn)動(dòng),也取決于系統(tǒng)本身的力學(xué)特性,如剛度、粘性與慣性等。緩沖包裝系統(tǒng)往往是非線性系統(tǒng),典型的有三次型、正切型和雙曲正切型等非線性系統(tǒng)。本課題主要以跌落沖擊工況下單自由度非線性自治包裝系統(tǒng)為研究對(duì)象,分別進(jìn)行了三個(gè)階段的研究:一般非線性保守系統(tǒng)自由振動(dòng)動(dòng)力學(xué)響應(yīng)分析、一般非線性耗散系統(tǒng)自由振動(dòng)動(dòng)力學(xué)響應(yīng)分析與一般非線性耗散系統(tǒng)跌落沖擊動(dòng)力學(xué)響應(yīng)分析。本文首先介紹了最大—最小值法(MMA)與同倫分析法(HAM)并以算例形式闡述了兩種方法的優(yōu)缺點(diǎn)。對(duì)于典型的正切型與雙曲正切型非線性自治系統(tǒng),兩種算法都需要對(duì)控制方程進(jìn)行近似簡(jiǎn)化,近似控制方程大大增加了分析誤差。對(duì)于這類更一般形式的二階非線性微分方程,本文提出了一種新的算法,可以簡(jiǎn)單有效地求解此類自由振動(dòng)響應(yīng)求解問(wèn)題�？紤]線性阻尼的影響,本文介紹了純非線性耗散系統(tǒng)響應(yīng)的Ateb函數(shù)表達(dá)解,進(jìn)而發(fā)展為三角函數(shù)的近似解析解。由于非線性的多樣性,不同形式的非線性系統(tǒng)可能具有相同的運(yùn)動(dòng)特征,進(jìn)行相同的運(yùn)動(dòng)。對(duì)于恢復(fù)力項(xiàng)更一般形式的耗散系統(tǒng)自由振動(dòng)問(wèn)題,提出了一般非線性微分方程的等效純非線性方程。在此基礎(chǔ)上,得到了非線性耗散系統(tǒng)自由振動(dòng)的響應(yīng)通解。結(jié)果與數(shù)值分析對(duì)比,準(zhǔn)確度較高,方法簡(jiǎn)單有效。緩沖包裝系統(tǒng)在跌落沖擊與自由振動(dòng)中具有相同的控制方程,但是初始條件的不同,運(yùn)動(dòng)特征有所區(qū)別。本文對(duì)三次型與正切型非線性包裝系統(tǒng)在保守形式與耗散形式下的動(dòng)態(tài)響應(yīng)分別進(jìn)行了分析,近似解析解與數(shù)值解非常接近。本文最后設(shè)計(jì)試驗(yàn)對(duì)理論計(jì)算進(jìn)行驗(yàn)證,選取空氣墊緩沖材料為試驗(yàn)樣品,分別在不同跌落高度與不同靜應(yīng)力下進(jìn)行重復(fù)試驗(yàn)。試驗(yàn)結(jié)果顯示空氣墊在不同條件下的沖擊壓縮過(guò)程中具有統(tǒng)一的力學(xué)行為規(guī)律,由此建立了動(dòng)態(tài)本構(gòu)關(guān)系,進(jìn)一步得到空氣墊作為緩沖材料時(shí)產(chǎn)品的動(dòng)力學(xué)控制方程。采用本文理論分析階段的算法得到了最大沖擊加速度與靜應(yīng)力關(guān)系,由此繪制出在不同跌落高度下的動(dòng)態(tài)緩沖曲線。理論值與實(shí)測(cè)值相當(dāng)吻合,表明了理論分析結(jié)果的正確性。
[Abstract]:In logistics, adverse conditions such as vibration and shock can cause product breakage. Buffer packaging is also an important part of product protection while optimizing and improving the product structure. The design of reliable packaging structure can effectively reduce the vibration and impact damage to the product. However, at present, the research of product protection dynamics in the adverse environment of logistics is relatively weak, and the packaging design of products is lack of in-depth and effective theoretical support and guidance. All kinds of practical cushioning packages can be abstracted as cushioning packaging system. The dynamic response characteristics of various types of packaging systems under various typical excitations are the theoretical basis of cushioning packaging design. The response of the buffer system depends not only on the force or motion of the environment, but also on the mechanical properties of the system, such as stiffness, viscosity and inertia. Cushioning packaging systems are usually nonlinear systems, such as cubic, tangent and hyperbolic tangent. In this paper, the nonlinear autonomous packaging system with order degree of freedom under the condition of drop impact is studied in three stages: the dynamic response analysis of free vibration of general nonlinear conservative system. The dynamic response analysis of free vibration of general nonlinear dissipative system and drop shock of general nonlinear dissipative system. In this paper, the Max-Minimum method (MMA) and Homotopy Analysis method (HAM) are introduced, and the advantages and disadvantages of the two methods are illustrated by an example. For a typical nonlinear autonomous system of tangent and hyperbolic tangent, both algorithms need to simplify the control equation approximately, and the approximate control equation greatly increases the analysis error. For this kind of second order nonlinear differential equation, a new algorithm is proposed, which can solve the problem of free vibration response simply and effectively. Considering the influence of linear damping, this paper introduces the Ateb function expression solution of the response of pure nonlinear dissipative system, and then develops into the approximate analytic solution of trigonometric function. Because of the diversity of nonlinearity, different nonlinear systems may have the same motion characteristics and the same motion. For the problem of free vibration of dissipative systems with more general form of restoring force term, the equivalent pure nonlinear equations of general nonlinear differential equations are proposed. On this basis, a general solution to the free vibration of a nonlinear dissipative system is obtained. Results compared with numerical analysis, the accuracy is high and the method is simple and effective. The cushioning packaging system has the same governing equation in the drop shock and free vibration, but the motion characteristics are different with different initial conditions. In this paper, the dynamic responses of cubic and tangent nonlinear packaging systems in conservative form and dissipative form are analyzed, respectively. The approximate analytical solution is very close to the numerical solution. At the end of this paper, the theoretical calculation is verified by designing experiments. The air cushion material is selected as the test sample, and repeated tests are carried out under different drop heights and different static stresses respectively. The experimental results show that the air cushion has a uniform mechanical behavior in the process of impact compression under different conditions. The dynamic constitutive relation is established and the dynamic governing equation of the product when the air cushion is used as the buffer material is obtained. The relationship between the maximum impact acceleration and the static stress is obtained by using the algorithm of the theoretical analysis stage in this paper, and the dynamic buffering curves at different drop heights are drawn. The theoretical values are in good agreement with the measured values, which indicates the correctness of the theoretical analysis results.
【學(xué)位授予單位】：江南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB48

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 陳鳴;陳安軍;;非線性包裝系統(tǒng)跌落沖擊響應(yīng)分析的HFAF法[J];包裝工程;2014年15期

2 王金梅;劉乘;;應(yīng)力-能量法求取泡沫塑料緩沖曲線時(shí)函數(shù)模型的研究[J];包裝工程;2014年05期

3 陳安軍;;非線性包裝系統(tǒng)跌落沖擊問(wèn)題變分迭代法[J];振動(dòng)與沖擊;2013年18期

4 盧富德;陶偉明;高德;;具有簡(jiǎn)支梁式易損部件的產(chǎn)品包裝系統(tǒng)跌落沖擊研究[J];振動(dòng)與沖擊;2012年15期

5 嚴(yán)敏;陳安軍;;跌落工況下斜支承系統(tǒng)響應(yīng)分析的變分迭代法[J];包裝工程;2012年13期

6 都學(xué)飛;歐陽(yáng)效卓;張汪年;;EPS緩沖材料的靜態(tài)壓縮性能的試驗(yàn)研究[J];包裝工程;2012年03期

7 劉乘;劉晶;;應(yīng)力-能量法在求取包裝材料最大加速度-靜應(yīng)力曲線方面的應(yīng)用分析[J];包裝工程;2011年01期

8 高德;盧富德;;具有轉(zhuǎn)動(dòng)包裝系統(tǒng)的正切非線性模型沖擊響應(yīng)研究[J];振動(dòng)與沖擊;2010年10期

9 黃秀玲;王軍;盧立新;王志偉;李明;;三次非線性包裝系統(tǒng)關(guān)鍵部件沖擊響應(yīng)影響因素分析[J];振動(dòng)與沖擊;2010年10期

10 陳安軍;;矩形脈沖激勵(lì)下斜支承彈簧系統(tǒng)沖擊特性的研究[J];振動(dòng)與沖擊;2010年10期

，

本文編號(hào)：2352293