Çiğdem DİNDAR, Hüseyin BEYTÜT, Selçuk KARAGÖZ

51CrV4 Yay Çeliğinde Isıl İşlemve Kesit Geometrisinin Çarpışma Dayanıklılığı Üzerine Etkisi

Bu çalışmada, 51CrV4 yay çeliği çarpışma kutusu malzemesi olarak kullanılmış ve çarpışma dayanıklılığı araştırılmıştır. Kare ve silindir kesit geometrisine sahip çarpışma kutuları SolidWorks programında tasarlanmış ve RADIOSS açık zaman entegrasyon yöntemi ve lineer olmayan sonlu elemanlar kodları ile çarpışma analizleri gerçekleştirilmiştir. Buna ek olarak, 51CrV4 çelik malzemesi 3 farklı ısıl işleme maruz bırakılarak mekanik özellikleri çekme ve sertlik testleri ile belirlenmiştir. Belirlenen mekanik özelliklere sahip yapının çarpışma dayanıklılığı, emilen enerji, maksimum çarpışma kuvveti, ortalama çarpışma kuvveti, çarpışma kuvveti verimi dikkate alınarak değerlendirilmiştir. Çarpışma kutularının kütleleri eşit olduğundan emilen enerji oranları özgül enerji emilim oranlarına eşittir. Isıl işlem uygulamasının ve kesit geometrisinin çarpışma dayanıklılığıüzerinde ciddi bir etkisi olduğu gözlemlenmiştir.

EFFECT OF HEAT TREATMENT AND CROSS SECTIONON THE CRASHWORTHINESS OF 51CRV4 SPRING STEEL

In this study,51CrV4 spring steel was used as a crash box material and its crashworthiness was investigated under axial dynamic loading. Crash boxes with cylinder and square geometries were designed in SolidWorks and crash analyseswere performed by using RADIOSS/explicit and nonlinear Finite Element (FE) codes. In addition, 51CrV4 spring steel was subjected to three different heat treatmentsandtheirmechanicalpropertiesweredeterminedbytensileandhardnesstests.The crashworthiness of crash boxwasevaluated taking into account the energy absorption (EA), peak crushing force (PCF), mean crushing force (MCF) and crash force efficiency (CFE). Since the crash boxes had equal mass, their EA rates are equal to specific energy absorption(SEA)rates.It has been observed that heat treatment and cross-section geometry have a serious impact on crashworthiness.

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