A lighter truck body only has value if the manufacturer can demonstrate that the structure still meets its load-carrying requirements and performs as designed after tare weight has been reduced.<\/p>\n
The difficulty is that vehicle buyers may not always be able to interpret structural calculations or material certificates. A familiar way of judging the structure may instead rely on a perception of thickness, such as tapping the side wall to see whether it feels “solid”.<\/p>\n
For this reason, in addition to technical documentation, the manufacturer needs a way to demonstrate structural performance that is visual, easy to check and repeatable on the actual vehicle. The objective is not to replace calculations with a simple measurement, but to help the buyer understand the relationship between material, structural design and actual structural behavior<\/strong>.<\/p>\n Tapping a truck body side wall may give an impression of plate thickness or local stiffness, but it does not indicate:<\/p>\n Two steel plates with different thicknesses may belong to different material grades and form part of completely different structural designs.<\/p>\n When explaining why a thinner truck body can still meet its load requirements, the manufacturer therefore needs to shift the focus from perceived thickness to material data, structural design and actual deformation<\/strong>.<\/p>\n The load-carrying capacity of a structural weight reduction solution can be demonstrated through three layers of evidence.<\/p>\n These three layers do not replace one another.<\/p>\n Material documentation does not demonstrate that the entire structure has sufficient load-carrying capacity.<\/p>\n Structural calculations do not replace confirmation that the correct material was actually used.<\/p>\n A deflection measurement does not replace calculation of the allowable deflection.<\/p>\n When used together, the three layers create an evidence chain from:<\/p>\n Material \u2192 Design \u2192 Observed performance on the actual vehicle<\/strong><\/p>\n A simple inspection can use a tensioned line and ruler to record floor deflection.<\/p>\n The important point is to keep the measurement method and position the same<\/strong>.<\/p>\n If the structure returns to its original condition, or close to the original condition according to the defined criterion, after unloading, the observed deformation is elastic.<\/p>\n If it does not return, permanent deformation may have occurred and needs to be evaluated.<\/p>\n This measurement allows the buyer to observe two different structural states directly:<\/p>\n Under load \u2192 the structure deforms<\/strong><\/p>\n After unloading \u2192 the structure recovers or does not recover<\/strong><\/p>\n However, the measurement only shows the actual deflection under the inspection condition. Whether that value is within the allowable limit still needs to be checked against the structural calculations and design requirements.<\/p>\n When a buyer questions a reduced plate thickness, simply saying “the new steel is better”<\/strong> or “this steel has higher strength”<\/strong> is usually not enough.<\/p>\n The manufacturer should provide three specific pieces of information.<\/p>\n The third point is particularly important because the buyer can often see it directly on the vehicle.<\/p>\n For example, if thickness is reduced while a flat plate with many stiffeners is replaced by a deeper formed section, the structural change can be visually identified.<\/p>\n The explanation is then no longer:<\/p>\n “The steel plate has become thinner.”<\/strong><\/p>\n Instead, it becomes:<\/p>\n “The material, thickness and cross-sectional geometry have been recalculated as a new structural solution.”<\/strong><\/p>\n A structural weight reduction solution should not end with the fabrication drawing.<\/p>\n The documentation needs to allow the relevant parties to verify the basis of the design.<\/p>\n The tare-weight comparison should be broken down by component rather than giving only one total number.<\/p>\n For example:<\/p>\n This presentation shows which design decisions created the weight reduction<\/strong>, rather than presenting only the final result.<\/p>\n The workshop and the end buyer do not need to read the same information in the same way.<\/p>\n The documentation can be divided into two levels.<\/p>\n Buyer-facing information should not be simplified until it becomes only a sales message.<\/p>\n It still needs to show:<\/p>\n A short document containing specific data is more useful than a page that simply claims the structure is “lighter but still strong”<\/strong>.<\/p>\n When a material with improved properties is introduced, not every solution needs to reduce thickness.<\/p>\n The material advantage can be used in two different ways.<\/p>\n These two approaches lead to different structural solutions.<\/p>\n If the customer prioritizes service life, the manufacturer may retain part of the original thickness rather than using the full material advantage for weight reduction.<\/p>\n If the objective is increased payload capacity, the design will focus more strongly on identifying where thickness can be reduced or cross-sectional geometry can be changed.<\/p>\n The objective therefore needs to be confirmed before calculations begin<\/strong>, not after the design has already been completed.<\/p>\n This knowledge series includes four cases with different recorded weight reductions.<\/p>\n These examples can be used to demonstrate that structural weight reduction through material and design changes has been achieved in practice.<\/p>\n However, they should not be used as default reduction percentages for another truck body.<\/p>\n Each case has a different:<\/p>\n The reduction percentage for any particular design can therefore only be determined after data from that specific design is available.<\/p>\n A good technical package should also identify what cannot be fully demonstrated at the time of vehicle delivery.<\/p>\n Fatigue calculations may target a design life based on defined assumptions.<\/p>\n This does not mean that every vehicle operating under every condition will achieve exactly the same number of cycles.<\/p>\n Similarly, a single deflection measurement when the vehicle is new cannot represent the full structural condition after several years of operation.<\/p>\n Post-service data is therefore a necessary continuation of the initial documentation.<\/p>\n Monitoring can be organized at three stages.<\/p>\n Immediately after delivery<\/strong><\/p>\n Measure deflection under the defined load condition to establish a baseline.<\/p>\n Record:<\/p>\n After 6 months<\/strong><\/p>\n Repeat the same method to check for changes relative to the baseline.<\/p>\n If operating conditions have changed significantly, record this to avoid comparing results from two non-equivalent conditions.<\/p>\n After 1 year<\/strong><\/p>\n Measure deflection again and inspect the connection areas that need monitoring, particularly those exposed to dynamic loading or identified during the design stage.<\/p>\n These three intervals are proposed monitoring points, not mandatory inspection cycles for every vehicle type.<\/p>\n The main value of the data series is comparability over time<\/strong>.<\/p>\n If the same design continues in production, data from the first vehicles can help the manufacturer review design assumptions and improve the documentation for subsequent vehicles.<\/p>\n A short inspection guide can be organized into four sections.<\/p>\n Inspection conditions<\/strong><\/p>\n State the required load condition and vehicle position.<\/p>\n Measurement position<\/strong><\/p>\n Mark the exact location on an image or drawing so that the same point can be used again.<\/p>\n Measurement method<\/strong><\/p>\n Explain how to tension the line, position the ruler and record the value.<\/p>\n How to interpret the result<\/strong><\/p>\n Explain clearly that:<\/p>\n This approach allows the measurement to be repeated months later without depending on the person who performed the first inspection.<\/p>\n The buyer can perform the deflection measurement directly according to the provided guidance.<\/p>\n The important point is that the same method needs to be used at different measurement times so that the data remains comparable<\/strong>.<\/p>\n First<\/strong>, measuring deflection with a tensioned line and ruler helps record actual deformation and distinguish the condition before and after unloading. This measurement does not determine the allowable deflection by itself.<\/p>\n Second<\/strong>, truck body load-carrying capacity needs to be demonstrated through the combination of the actual material, structural calculations and fabrication records. No single layer of evidence replaces all the others.<\/p>\n Third<\/strong>, published structural weight reduction cases are reference examples only. The reduction achieved in another case should not be used as a commitment for a vehicle that has not been weighed and recalculated.<\/p>\n Fourth<\/strong>, fatigue life depends on repeated loading during operation. A calculation provides a design life based on defined assumptions, not an absolute guarantee under every operating condition.<\/p>\n Fifth<\/strong>, post-delivery monitoring needs to use the same method and sufficiently comparable conditions for the results to remain meaningful.<\/p>\n Sixth<\/strong>, the vehicle should not be deliberately overloaded simply to demonstrate load-carrying capacity. Evaluation needs to remain within the design conditions, operating limits and requirements applicable to the vehicle.<\/p>\n A lighter design becomes more convincing when the buyer is not only given an explanation but can follow the complete basis of the solution: which material was used, how the structure was calculated, where the weight was reduced and how the vehicle deforms under actual load<\/strong>.<\/p>\n When this information is recorded from delivery and then compared during operation, the value of the structural weight reduction solution is demonstrated through the operating records of the structure itself.<\/p>\n <\/p>\n","protected":false},"featured_media":8735,"parent":9455,"menu_order":6,"template":"","meta":{"_acf_changed":false,"inline_featured_image":false},"danh-muc-kien-thuc":[276],"class_list":["post-9476","kien-thuc","type-kien-thuc","status-publish","has-post-thumbnail","hentry","danh-muc-kien-thuc-structural-weight-reduction"],"acf":[],"_links":{"self":[{"href":"https:\/\/giaanh.vn\/en\/wp-json\/wp\/v2\/kien-thuc\/9476","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/giaanh.vn\/en\/wp-json\/wp\/v2\/kien-thuc"}],"about":[{"href":"https:\/\/giaanh.vn\/en\/wp-json\/wp\/v2\/types\/kien-thuc"}],"up":[{"embeddable":true,"href":"https:\/\/giaanh.vn\/en\/wp-json\/wp\/v2\/kien-thuc\/9455"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/giaanh.vn\/en\/wp-json\/wp\/v2\/media\/8735"}],"wp:attachment":[{"href":"https:\/\/giaanh.vn\/en\/wp-json\/wp\/v2\/media?parent=9476"}],"wp:term":[{"taxonomy":"danh-muc-kien-thuc","embeddable":true,"href":"https:\/\/giaanh.vn\/en\/wp-json\/wp\/v2\/danh-muc-kien-thuc?post=9476"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}1. Thickness alone does not demonstrate load-carrying capacity<\/span><\/h2>\n
\n
2. Three layers of evidence need to work together<\/span><\/h2>\n
\n\n
\n \nEvidence layer<\/th>\n Content<\/th>\n Value to the buyer<\/th>\n<\/tr>\n<\/thead>\n \n Material<\/td>\n Material documentation, yield strength grade, thickness and traceability<\/td>\n Confirms whether the actual material matches the design<\/td>\n<\/tr>\n \n Structural calculations<\/td>\n Calculations according to the applicable standard, confirmed by an authorized person<\/td>\n Demonstrates the technical basis for thickness, cross-section and connections<\/td>\n<\/tr>\n \n Actual inspection<\/td>\n Deflection measurement on the vehicle under load and after unloading<\/td>\n Allows the buyer to observe directly how the structure behaves<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 3. Measure deflection so the buyer can observe structural behavior directly<\/span><\/h2>\n
\n\n
\n \nStep<\/th>\n Method<\/th>\n<\/tr>\n<\/thead>\n \n 1<\/td>\n Bring the vehicle to the defined load condition for the inspection<\/td>\n<\/tr>\n \n 2<\/td>\n Tension a line between two defined points on the floor<\/td>\n<\/tr>\n \n 3<\/td>\n Measure the gap at mid-span<\/td>\n<\/tr>\n \n 4<\/td>\n Unload the vehicle and repeat the measurement at the same position<\/td>\n<\/tr>\n \n 5<\/td>\n If comparison with an older vehicle is required, use the same method on both vehicles<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 4. Three figures help explain why a truck body can be thinner<\/span><\/h2>\n
\n\n
\n \nInformation<\/th>\n What it helps explain<\/th>\n<\/tr>\n<\/thead>\n \n Yield strength grade of the material<\/td>\n Shows how the stress level before permanent deformation has changed<\/td>\n<\/tr>\n \n Calculated deflection<\/td>\n Shows that deformation has still been checked after thickness reduction<\/td>\n<\/tr>\n \n Geometric compensation<\/td>\n Shows where stiffeners, sections or structural details have been changed<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 5. Documentation that should accompany a structural weight reduction solution<\/span><\/h2>\n
\n\n
\n \nDocument<\/th>\n Main user<\/th>\n Purpose<\/th>\n<\/tr>\n<\/thead>\n \n Component-by-component tare-weight comparison before and after redesign<\/td>\n Vehicle owner, manufacturer<\/td>\n Shows where mass has changed<\/td>\n<\/tr>\n \n Structural calculations according to the applicable standard<\/td>\n Technical team, reviewer<\/td>\n Demonstrates the basis for thickness and geometry<\/td>\n<\/tr>\n \n Material documentation and traceability records<\/td>\n Quality department<\/td>\n Confirms that the actual material matches the design requirements<\/td>\n<\/tr>\n \n Relevant welding and fabrication records<\/td>\n Workshop, quality department<\/td>\n Confirms that fabrication was performed according to the required process<\/td>\n<\/tr>\n \n Deflection measurement guide<\/td>\n Buyer, operator<\/td>\n Allows the inspection to be repeated using the same method<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n
6. Technical documentation and buyer-facing information should use different levels of detail<\/span><\/h2>\n
\n\n
\n \nReader<\/th>\n Information to prioritize<\/th>\n<\/tr>\n<\/thead>\n \n Workshop and technical team<\/td>\n Calculations, materials, thickness, welding procedure, bending radius, connection details<\/td>\n<\/tr>\n \n Vehicle buyer<\/td>\n Weight reduction achieved, three key structural figures and actual inspection guidance<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n
7. Define in advance how the material advantage will be used<\/span><\/h2>\n
\n\n
\n \nApproach<\/th>\n Main objective<\/th>\n<\/tr>\n<\/thead>\n \n Retain thickness<\/td>\n Increase service life or increase reserve at the operating position<\/td>\n<\/tr>\n \n Reduce thickness<\/td>\n Reduce tare weight and increase payload capacity within the permitted limits<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 8. Reference cases demonstrate possibility, not a guaranteed reduction percentage<\/span><\/h2>\n
\n\n
\n \nAppropriate use<\/th>\n Inappropriate use<\/th>\n<\/tr>\n<\/thead>\n \n Understand the level of change achieved in some designs<\/td>\n Guarantee a reduction for a vehicle that has not yet been surveyed<\/td>\n<\/tr>\n \n Illustrate the role of material changes combined with geometry changes<\/td>\n Apply one percentage to every truck body<\/td>\n<\/tr>\n \n Establish an initial expectation before survey<\/td>\n Replace weighing and recalculation of the actual design<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n
9. Some performance aspects can only be confirmed more clearly after operation<\/span><\/h2>\n
\n\n
\n \nItem<\/th>\n Limitation at delivery<\/th>\n<\/tr>\n<\/thead>\n \n Weld fatigue life<\/td>\n Depends on actual load cycles and operating history<\/td>\n<\/tr>\n \n Long-term deflection<\/td>\n Depends on loading, route conditions and vehicle use<\/td>\n<\/tr>\n \n Behavior under overload<\/td>\n Actual overload should not be created simply to demonstrate the structure<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 10. Post-delivery monitoring creates actual operating data<\/span><\/h2>\n
\n
11. How to organize a one-page inspection guide for the buyer<\/span><\/h2>\n
\n
12. Responsibilities of the different functions<\/span><\/h2>\n
\n\n
\n \nTask<\/th>\n Responsible person or function<\/th>\n<\/tr>\n<\/thead>\n \n Weigh and prepare the before-and-after tare-weight comparison<\/td>\n Workshop in coordination with the technical function<\/td>\n<\/tr>\n \n Perform structural calculations<\/td>\n Authorized structural design function<\/td>\n<\/tr>\n \n Confirm structural calculations<\/td>\n Authorized person according to the applicable requirements<\/td>\n<\/tr>\n \n Provide and verify material documentation<\/td>\n Supplier in coordination with the quality department<\/td>\n<\/tr>\n \n Prepare the deflection measurement guide<\/td>\n Technical team<\/td>\n<\/tr>\n \n Perform the initial measurement<\/td>\n Workshop in coordination with the customer<\/td>\n<\/tr>\n \n Retain the baseline record<\/td>\n Workshop and operator<\/td>\n<\/tr>\n \n Repeat measurements at monitoring intervals<\/td>\n Operator in coordination with the technical team<\/td>\n<\/tr>\n \n Evaluate deformation or cracking when identified<\/td>\n Technical function responsible for the design<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 13. Notes on applying this knowledge<\/span><\/h2>\n