<p>Norrborns Industri AB in Bollnäs manufactures truck trailers with the brand Parator. One of their trailers is Parator LX 10-20. The trailer is designed to transport hooklift containers with the option to tip loose goods such as gravel, asphalt and seed. The container is mounted on a frame which is placed on the chassis. To reduce weight a redesign of the trailer is needed. The purpose of this study was to develop a concept that makes the frame lighter and easier to manufacture while maintaining safety and rigidity. The thesis also discusses factors to consider when designing with high-strength steel.</p><p> </p><p>The optimization was based on existing 2D drawings of the frame. Analysis of the structure served as a basis for the optimization. First, a 3D model was created from the drawings. Then, the frame was analyzed with selected loads and boundary conditions. Initially simple models were used to develop concepts. From these, two concepts were selected and one of them was thoroughly analyzed.</p><p> </p><p>The optimization resulted in a concept design weight of 732 kg, which is 179 kg less compared to the current frame at 911 kg.</p> / <p>Norrborns Industri AB i Bollnäs tillverkar lastbilssläp som säljs under varumärket Parator. Ett av deras släp är Parator LX 10-20 som är en lastväxlarvagn avsedd för att transportera olika lastbärare, t ex grusflak och containrar, som behöver kunna tippas. Lastbäraren sitter monterad på en tippram som i sin tur sitter på ett släpchassi. En omkonstruktion av detta släp önskas för att minska vikten. Syftet med examensarbetet var att ta fram förslag som gör tippramen lättare samt enklare att tillverka med bibehållen säkerhet och vridstyvhet. Examensarbetet tar även upp faktorer att tänka på vid konstruktion med höghållfast stål.</p><p> </p><p>Optimeringen utgick från befintliga 2D-ritningar på ramen. Först skapades en 3D-modell från ritningarna. Sedan analyserades ramen utifrån valda laster och randvillkor. Analyserna av den nuvarande konstruktionen låg sedan till grund för optimeringen. Till en början användes enklare modeller för att ta fram koncept. Därefter modellerades två valda koncept varpå ett av dem har analyserats mer genomgående.</p><p> </p><p>Arbetet resulterade i ett koncept som vägde 732 kg. Det är 179 kg lättare än den nuvarande konstruktionen på 911 kg.</p>

Norrborns Industri AB in Bollnäs manufactures truck trailers with the brand Parator. One of their trailers is Parator LX 10-20. The trailer is designed to transport hooklift containers with the option to tip loose goods such as gravel, asphalt and seed. The container is mounted on a frame which is placed on the chassis. To reduce weight a redesign of the trailer is needed. The purpose of this study was to develop a concept that makes the frame lighter and easier to manufacture while maintaining safety and rigidity. The thesis also discusses factors to consider when designing with high-strength steel.   The optimization was based on existing 2D drawings of the frame. Analysis of the structure served as a basis for the optimization. First, a 3D model was created from the drawings. Then, the frame was analyzed with selected loads and boundary conditions. Initially simple models were used to develop concepts. From these, two concepts were selected and one of them was thoroughly analyzed.   The optimization resulted in a concept design weight of 732 kg, which is 179 kg less compared to the current frame at 911 kg. / Norrborns Industri AB i Bollnäs tillverkar lastbilssläp som säljs under varumärket Parator. Ett av deras släp är Parator LX 10-20 som är en lastväxlarvagn avsedd för att transportera olika lastbärare, t ex grusflak och containrar, som behöver kunna tippas. Lastbäraren sitter monterad på en tippram som i sin tur sitter på ett släpchassi. En omkonstruktion av detta släp önskas för att minska vikten. Syftet med examensarbetet var att ta fram förslag som gör tippramen lättare samt enklare att tillverka med bibehållen säkerhet och vridstyvhet. Examensarbetet tar även upp faktorer att tänka på vid konstruktion med höghållfast stål.   Optimeringen utgick från befintliga 2D-ritningar på ramen. Först skapades en 3D-modell från ritningarna. Sedan analyserades ramen utifrån valda laster och randvillkor. Analyserna av den nuvarande konstruktionen låg sedan till grund för optimeringen. Till en början användes enklare modeller för att ta fram koncept. Därefter modellerades två valda koncept varpå ett av dem har analyserats mer genomgående.   Arbetet resulterade i ett koncept som vägde 732 kg. Det är 179 kg lättare än den nuvarande konstruktionen på 911 kg.

Examensarbetet är en studie av den fasta delen av takkonstruktionen i Swedbank Arena. Syftet med examensarbetet är att undersöka hur valet av att använda höghållfast stål påverkat kostnader och miljö under hela konstruktionens livstid. I undersökningen har takkonstruktionen dimensionerats med tre olika alternativ där andelen höghållfast stål i konstruktionen har varierats. Nedan beskrivs översiktligt de stålsorter som alternativen är uppbyggda av.   -          Alternativ A innehåller endast konventionellt stål som har sträckgräns 355 MPa. -          Alternativ B är det alternativ som byggts i verkligheten. Den verkliga konstruktionen innehåller stålsorter med sträckgränser mellan 355 MPa - 900 MPa. -          Alternativ C innehåller en större andel höghållfast stål än den verkliga konstruktionen. Detta alternativ innehåller stålsorter med sträckgränser 355- 900 MPa.   Dimensioneringen av takkonstruktionen har utförts med programmet Autodesk Robot Structural Analysis Professional 2010 som innehåller automatisk normkontroll enligt Boverkets handbok om stålkonstruktioner, BSK07. I analysen har två modeller skapats, alternativ A och C, för att kunna jämföras med den verkliga takkonstruktionen, alternativ B. Resultaten från analysen har använts i beräkningarna av kostnad och miljöpåverkan.   För att beräkna miljöpåverkan användes ett livscykelanalysverktyg som är speciellt utvecklat för stål. I studien jämfördes miljöpåverkan för alternativen med höghållfast stål med ett alternativ som endast består av konventionellt stål. Det har antagits att miljöpåverkan under profiltillverkning, montage och användningsfasen är lika stora eller försumbar för studien. Miljöstudien är en jämförelsestudie. Det innebär att områden i konstruktionens livscykel som resulterar i lika stor miljöpåverkan för samtliga alternativ inte tas med i beräkningen.   Kostnadsberäkningen har genomförts i samarbete med Ruukki. Med resultaten från analysen i Robot skapades ett frågeunderlag som Ruukki använde för att beräkna de totala kostnaderna för samtliga alternativ. Det som Ruukki beaktade vid prissättningen var materialpris, svetsning i verkstad, målning, transport och eventuellt byte av kran vid montage. I kostnadsanalysen har det antagits att projekteringskostnader och användning av takkonstruktionen är densamma för samtliga alternativ. Kostnadsanalysen har utförts som en jämförelsestudie mellan de olika alternativen.   Stålmängderna minskar när man använder sig av höghållfast stål. Detta har medfört att både den totala kostnaden och miljöpåverkan för den verkliga konstruktionen blivit lägre i jämförelse med en konstruktion som endast består av konventionellt stål. Genom att använda höghållfast stål har man sparat mycket pengar och samtidigt reducerat miljöpåverkan. / The thesis is a study of the fixed part of the roof structure in Swedbank Arena. The purpose of the study is to investigate how the choice of using high strength steel has influenced costs and environmental impact throughout the entire life cycle. The roof has been designed with three different alternatives in which the proportion of the high-strength has varied. The following text describes briefly which grades the alternatives are composed of.   -          Alternative A contains only conventional steel with a yield strength of 355 MPa. -          Alternative B is the design that has been built. This structure contains steel with a yield strength between 355- 900 MPa. -          Alternative C contains a larger proportion of high-strength steel than the existening construction. This alternative contains steel with a yield strength between 355-900 MPa.   The calculations of the roof structure have been performed with the program Autodesk Robot Structural Analysis Professional 2010 which has an automatic code check according to BSK07, a publication from the Swedish national Board of Housing, Building and Planning. Two different models, alternative A and C, have been created and compared with the real structure, alternative B. The results from this analysis have been used in the calculations of cost and environmental impact.   In the calculations of environmental impact a life cycle analysis tool was used that has been developed especially for steel. The study compared the environmental impact of the alternatives with high strength steel with the alternative that only consists of conventional steel. It has been assumed that the environmental impact in the manufacturing of the profiles, assembly of the steel construction and the use phase is equal or negligible for the study. The environmental study is a comparison study. This means that parts of the constructions life cycle that result in an equal environment impact for all alternatives are not calculated in the study.   The cost estimation was calculated in collaboration with Ruukki. The result of the analysis in Robot was used as a tender request that Ruukki used to calculate the total costs of all alternatives. In the cost calculations Ruukki took into account the differences in material prices, welding in the steel factory, painting, transportation and possible replacement of the crane during assembly. In the cost analysis it has been assumed that the cost of designing the roof structure and the use phase is the same for all alternatives. The cost analysis has been performed as a comparison study between the different alternatives.   The result of the study shows that the steel volume decreased when the structure consists of high strength steel. The decrease of the steel volume resulted in a reduced total cost and environmental impact. By using high strength steel a lot of money has been saved and in the same time the environmental impact has decreased. The thesis is a study of the fixed part of the roof structure in Swedbank Arena. The purpose of the study is to investigate how the choice of using high strength steel has influenced costs and environmental impact throughout the entire life cycle. The roof has been designed with three different alternatives in which the proportion of the high-strength has varied. The following text describes briefly which grades the alternatives are composed of.   -          Alternative A contains only conventional steel with a yield strength of 355 MPa. -          Alternative B is the design that has been built. This structure contains steel with a yield strength between 355- 900 MPa. -          Alternative C contains a larger proportion of high-strength steel than the existening construction. This alternative contains steel with a yield strength between 355-900 MPa.   The calculations of the roof structure have been performed with the program Autodesk Robot Structural Analysis Professional 2010 which has an automatic code check according to BSK07, a publication from the Swedish national Board of Housing, Building and Planning. Two different models, alternative A and C, have been created and compared with the real structure, alternative B. The results from this analysis have been used in the calculations of cost and environmental impact.   In the calculations of environmental impact a life cycle analysis tool was used that has been developed especially for steel. The study compared the environmental impact of the alternatives with high strength steel with the alternative that only consists of conventional steel. It has been assumed that the environmental impact in the manufacturing of the profiles, assembly of the steel construction and the use phase is equal or negligible for the study. The environmental study is a comparison study. This means that parts of the constructions life cycle that result in an equal environment impact for all alternatives are not calculated in the study.   The cost estimation was calculated in collaboration with Ruukki. The result of the analysis in Robot was used as a tender request that Ruukki used to calculate the total costs of all alternatives. In the cost calculations Ruukki took into account the differences in material prices, welding in the steel factory, painting, transportation and possible replacement of the crane during assembly. In the cost analysis it has been assumed that the cost of designing the roof structure and the use phase is the same for all alternatives. The cost analysis has been performed as a comparison study between the different alternatives.   The result of the study shows that the steel volume decreased when the structure consists of high strength steel. The decrease of the steel volume resulted in a reduced total cost and environmental impact. By using high strength steel a lot of money has been saved and in the same time the environmental impact has decreased.

Different kinds of bridges require different kinds of bearings. The Swedish Traffic Agency (Trafikverket) maintains 53 bridges in Sweden with high strength steel roller bearings. These kinds of bearings may cause failure due to fatigue and corrosion and therefore they need to be replaced as a safety reason. Swedish Traffic Agency has been working on the replacement since 2011 and this study is aimed at four different bridges maintained by the Swedish Traffic Agency where bearing replacement is completed or planned. Bridges with high strength steel roller bearings are dimensioned according to old norms which didn’t require dimensioning for bearing replacement. This creates problems when the superstructure needs to be lifted with hydraulic jacks to unload the bearings during the replacement. These problems are repetitive and consist for example of lack of space and construction parts that aren’t dimensioned to handle the loads that occur during the lift of the superstructure. Therefor some kind of temporary construction is arranged to solve the problems. The purpose of the study is to compare methods and cost for bearing replacement, safety solutions and the use of temporary bearings for three types of supports. This study has dealt with three different kinds of supports: circular column, abutment and wall pier, where four different methods of bearing replacement have been compared. Through interviews, observation of blueprints and literature studies a comparison between methods has been made.  The temporary constructions are made of steel or concrete. Results of the study shows that a temporary construction made of steel is more adaptable but more expensive than a temporary construction made of concrete. A temporary construction made of concrete requires a greater encroachment of the structure. Bridge structures are complex constructions whom may differ from each other. The individual bridge’s unique location, shape and type are factors that affect the choice of method. This had led to difficulties to define the best bridge bearing replacement method. Constructions of steel are expensive and should, if possible, be reused. When using of the method of temporary concrete construction the structure should be dimensioned for permanent use.

I detta examensarbete utförs en jämförelse av HSQ-balkar och VKR- pelare i hållfasthetsklass S355 respektive S460. I arbetet dimensioneras profiler anpassade efter studerade fiktiva konstruktioner och ställs emot varandra. Syftet är att optimera profilerna och effektivisera stålanvändningen. Förhoppningen är att en applicering av höghållfast stål i vanliga konstruktioner medför en reducerad stålmängd. Är minskningen tillräckligt stor bidrar denna i sin tur till en mindre miljöpåverkan samt kostnadseffektiva dimensioneringslösningar. Två olika byggnadsstommar utförda i stål med sträckgränsen 355 respektive 460 MPa undersöks. Huvudkonstruktionen studeras i delalternativ beroende på en variation av upplagsfall och stålklass vilket påverkar dimensioneringen av profilerna. Resultaten används för att göra en miljö- och kostnadsanalys. Rapporten visar blandade resultat. Det finns besparingar att göra men inte i alla avseenden. Miljöanalysen visar att koldioxidutsläppet minskar i de alternativ där stålmängden reducerats. En prisuppskattning av de framtagna profilerna visar att inga kostnadsbesparingar kan göras då alla balkar och pelare i den studerade konstruktionen byts ut till stål med en högre hållfasthetsklass. I de enskilda fall där materialbesparingen är över 10 % kan kostnadsbesparingar göras. / The thesis is a comparison of HSQ-beams and VKR-columns of strength grade S355 and S460. In this study, profiles designed for two different fictional construction frames are compared to each other. The aim is to optimize the profiles and streamline the steel use. Hopefully the usage of high-strength steel in ordinary structures results in a reduced amount of steel. If the decrease is sufficiently large it contributes to a reduced environmental impact and cost effective solutions. Two separate building frames made in both steel with yield strength of 355 and 460 MPa are examined. The main structure is studied in sub-options depending on a variety of support case and steel grade which affects the design of the profiles. The results are used to analyze their impact on costs and environment. The report shows mixed results. There are savings to be made but not in all respects. Environmental analysis shows that carbon dioxide emissions decrease in the options where the steel amount is reduced. A price estimation of the profiles show that no savings can be made when the entire studied structure is upgraded to a high strength steel. However, cost savings can be made in individual cases where the material savings is 10 % higher.

Purpose: The purpose of this study has been to investigate the essentials of being able to incorporate high-strength steels (460 MPa and beyond) for structural elements in buildings. As of late, structural steels with a yield point of 355 MPa have been considered standard and have been for the past decade. One of the problems that occur with an increased yield point, is that deflection of structural elements increases, as the Young’s modulus does not increase with increasing yield point. Welding, stability, behavior during fire, and fatigue are also subjects of interest. Method: The study was conducted through several courses of action: a literature review covering the latest research of high-strength steels within the sought-after area of interest, followed by calculations of a truss resting on two columns, being subject to bending moment and compressive force, in both 355 MPa and 700 MPa, in order to review the differences that occur and how they can be counteracted. Lastly, interviews were carried out, where structural engineers gave their thoughts and experiences on the matter at hand. Results: The results show that welding is one of the largest hurdles with being able to utilize high-strength structural steels, though there are newer, more promising methods of welding which can be used, such as electron beam welding. Regarding structural integrity and buckling of structural elements, high-strength steel can be used for trusses, where the structural members are mainly being pulled, opposed to being subject to compressive force. This was shown with the performed calculations, during the interviews, and by the literature overview. Conclusions: The general conclusions of the study is that for welding, further research, education, and training is required for all concerned parts, such as the structural engineers and the on-site welders, which will increase the knowledge regarding how welding of high-strength steels should be performed, but also raise awareness about newer and more modern methods. Fire behavior for high-strength steels are a higher risk factor that should be treated and executed with higher degrees of caution by engineers. Reduction factors for fire affected steel construction elements should be corrected to fit the behavior for high-strength steels as well, as they differ from the current Eurocode 3 for lower class steels. Problems with instability can be counteracted by utilizing the steel in pulled structural members, such as trusses and struts. Lastly, for high-strength steels to be used more widely, structural engineers and manufacturers need to work together for any of the two to profit, as low production rates are costly.